RESUMEN
Acute embolic or local thrombotic ischaemia of the upper limbs can be treated by embolectomy or by endovascular techniques. We report here on the endovascular thrombectomy of acute embolic occlusions of subclavian and axillary arteries in two patients using a rotational thrombectomy device and give an overview about the actual literature. Two female patients, each with a history of multivessel coronary disease and intermittent atrial fibrillation, complained of sudden onset of pain at rest and paleness of the left and right arm, respectively. Duplex ultrasound showed a localized embolic occlusion of the left subclavian artery and the bifurcation of the brachial artery in the first patient and a localized embolic occlusion of the distal right subclavian and axillary artery in the second patient. In the first patient, the left subclavian artery was reopened using a 8F-Rotarex device via the femoral access, while the bifurcation of the brachial artery was reopened by local thrombolysis using 25 mg rt-PA because of the insufficient length of the thrombectomy device of 80 cm. In the second patient, the right subclavian and axillary arteries were reopened using a 6F-Rotarex device. Follow-up examinations before discharge and after 6 months showed normalized perfusion of the arms of both patients.
Asunto(s)
Angioplastia/instrumentación , Arteria Axilar/cirugía , Embolia/cirugía , Arteria Subclavia/cirugía , Trombectomía/instrumentación , Enfermedad Aguda , Anciano , Anciano de 80 o más Años , Brazo/irrigación sanguínea , Arteria Axilar/diagnóstico por imagen , Embolia/diagnóstico por imagen , Diseño de Equipo , Femenino , Humanos , Isquemia/diagnóstico por imagen , Isquemia/cirugía , Radiografía , Arteria Subclavia/diagnóstico por imagenRESUMEN
AIM: In coronary heart disease, the surgical therapy of choice is the construction of an artenal bypass of the left anterior descending artery (LAD) using the internal thoracic artery 8ITA). We define age dependent normal values for the ITA such as diameter of the lumen (LD), peak systolic (Vs) and diastolic (Vd) flow velocity and the ratio of these two values (SDR) measured by duplex ultrasound. Furthermore, the modification and pathological changes of the Doppler curve after minimal invasive bypass of the LAD (MIDCAB) are described. MATERIAL AND METHODS: 96 people, age 18 - 87 years, subdivided into 6 age groups were examined by duplex to define the normal values of the ITA, and 55 patients (mean age 63 +/- 10 years, 48 men, 7 women) were evaluated after MIDCAB-surgery to describe the postoperative modification of the Doppler curve. The examinations were performed using a 4 - 7 MHz linear ultrasound transducer in the right and left 1. or 2. intercostal space parasternally. RESULTS: In all 96 people, the ITA was detectable on both sides presenting a typical bi- or triphasic Doppler flow profile. A linear age dependent increase in the LD of 1.95 +/- 0.15 mm (right ITA) and 1.93 +/- 0.27 mm (left ITA) respectively to 2.65 +/- 0.48 mm and 2.55 +/- 0.43 mm was found. No significant side difference was found for Vs and Vd, nor were there any age dependent differences for Vs. The SDR showed an age dependent linear increase on the right side from 3.5 +/- 1.1 to 6.1 +/- 2.2, p < 0.0012, and on the left from 3.9 +/- 1.2 to 6.7 +/- 1.7, p < 0.0001. Postoperatively, the Doppler spectrum was modified into a mono- or biphasic Doppler curve with a reduced Vs and an increased Vd resulting in a significantly decreased SDR on the left side compared with the right side (1.3 +/- 0.8 vs. 5.4 +/- 2.0, p < 0.00001). Three patients with angiographically proven graft failure had an SDR of 2.6 - 5.2 (mean 3.8), as opposed to a value of < 2.0 in case of a patent bypass. An SDR > 2.0 has a sensitivity of 100 % and a specificity of 97 % in the detection of a haemodynamically relevant (>70 %) ITA-graft-stenosis. CONCLUSIONS: With rising age, there is an increase in the LD of the ITA and the peripheral resistance, expressed as SDR. After MIDCAB surgery the former triphasic Doppler flow curve changes into a mono- or biphasic curve corresponding to the coronary blood flow. An SDR >2.0 is a strong indicator of bypass failure.
Asunto(s)
Arterias Torácicas/diagnóstico por imagen , Ultrasonografía Doppler , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia , Arterias Torácicas/crecimiento & desarrolloRESUMEN
BACKGROUND: To evaluate the efficacy, safety and limitation of a new 6F-compatible nitinol stent (Dynalink(TM). MATERIAL AND METHODS: We treated 50 patients (17 women, 33 men, mean age 72 +/- 8 years) by implanting 80 Dynalink(TM)-stents into 75 vessels during a 6-month period. Target lesions were: iliac artery: 25, femoral artery: 31, popliteal artery: 16, femoro-popliteal bypass: 5, subclavian vein: 3. Preinterventional Rutherford classifications: Class 1 : 3 legs (5 %), class 2 : 27 legs (51 %), class 3 : 16 legs (31 %), class 4 : 2 legs (4 %), class 5 : 5 legs (9 %). 40 % stents each were implanted ipsilateral, 60 % cross-over. RESULTS: All interventions were successful regardless of a sometimes anatomically difficult access to the lesion. The device was characterised by a high flexibility and radial force and the stent did not shorten. COMPLICATIONS: One distal stent dislocation during placement occurred, no puncture site complication. The mean diameter stenosis was reduced from 91 +/- 10 % (75 - 100 %) to 4 +/- 8 % (0 - 30 %). The ankle-brachial index was improved from 0.46 +/- 0.22 to 0.75 +/- 0.23 (p < 0.001). Post-interventional Rutherford classifications: Class 0 : 43 legs (81 %), class 1 : 5 legs (4,5 %), class 5 : 5 legs (4,5 %). CONCLUSIONS: The new 6F-sheath compatible nitinol stent is characterised by a good flexibility, radial force, and a lack of shortening. By the reduction of the diameter of the device to 6F, the potential risk of a local bleeding complication may be reduced and 6F sealing devices will be usable. Disadvantages are the 0.018 inch guide-wire lumen and the limited stent sizes.
Asunto(s)
Aleaciones , Angioplastia de Balón , Arteriopatías Oclusivas/terapia , Pierna/irrigación sanguínea , Stents , Adulto , Anciano , Anciano de 80 o más Años , Angiografía , Arteriopatías Oclusivas/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Stents/efectos adversosRESUMEN
AIM: Although colour coded Doppler ultrasound (CCDU) is established as a non-invasive diagnostic tool for detecting renal artery stenoses (RAS), no uniform criterion for defining a hemodynamically relevant stenosis (i.e. angiographic stenosis of > or = 70% of the diameter) exists. We therefore investigated the predictive value of the renal-aortic flow-velocity ratio (RAR) > 3.5 m/s and a difference of < 0.05 between the left and right side for the resistance index according to Pourcelot (dRI) in the detection of a relevant RAS. PATIENTS AND METHODS: We analysed 500 consecutive CCDU examinations of patients with hypertension retrospectively. An RAR > 3.5 and/or a lateral inequality of the RI < 0.05 were used as stenosis criterion. RESULTS: In 448 patients (90%) both renal arteries could be found, in 11 patients (2%) only the right artery, in 6 patients (1%) the left artery, and in 35 patients (7%) no renal artery was detectable. In 98 patients (19.6%), RAS was diagnosed, 69 (71%) of them underwent angiography. 38 patients presented an RAR > 3.5 plus dRI > 0.05. In 29 of these, angiography was performed. 96% of them presented with an RAS of > or = 70% and 4% showed an RAS of 40-69% (specificity 97%, sensitivity 76%). In 54 patients the RAR was > 3.5, but dRI < 0.05. 24% of the patients undergoing angiography (n = 37) presented with an RAS of > or = 70%, 68% with an RAS of 40-69%, and 8% with an RAS of < 40% (specificity 60%, sensitivity 100%). 44 hypertensive patients who underwent angiography after a CCDU examination not suggesting the presence of RAS were used as control group. CONCLUSION: An experienced physician using a high quality colour-coded duplex-machine can reliably detect the renal arteries. The presence of RAS can be diagnosed with certainty by CCDU applying the criterion of RAR > 3.5, but the diagnosis of a one-sided haemodynamically relevant RAS can only be certain if the criterion of dRI > 0.05 is used in addition.
Asunto(s)
Hemodinámica/fisiología , Obstrucción de la Arteria Renal/diagnóstico por imagen , Ultrasonografía Doppler en Color , Aorta Abdominal/diagnóstico por imagen , Aorta Abdominal/fisiopatología , Velocidad del Flujo Sanguíneo/fisiología , Femenino , Humanos , Hipertensión Renovascular/diagnóstico por imagen , Hipertensión Renovascular/fisiopatología , Masculino , Arteria Renal/diagnóstico por imagen , Arteria Renal/fisiopatología , Obstrucción de la Arteria Renal/fisiopatología , Estudios Retrospectivos , Sensibilidad y Especificidad , Resistencia Vascular/fisiologíaRESUMEN
BACKGROUND: To evaluate the efficacy, safety and limitations of a new rotational thrombectomy device (Straub-Rotarex) in clinical practice. MATERIAL AND METHODS: The Straub-Rotarex catheter is a new, wire-guided rotational thrombectomy device for the treatment of acute and subacute occlusions of the femoro-popliteal arteries. Over a 6-month period, 28 patients (64% male, mean age 69 +/- 9.5, 51-91 years) with 31 legs, mean duration of occlusion 4.4 +/- 4 (0-20) weeks, mean occlusion length 22 +/- 11 (5-40) cm were treated with the device, 5 of them in a cross-over technique. Target lesions: Aortic-femoral bypass, common iliac artery, external iliac artery, common femoral artery: 1 each, superficial femoral artery: 23, popliteal artery: 17. Initial stage of claudication: IIa: 6%, IIb: 72%, III: 16%, IV: 6%. RESULTS: Primary success rate: 90% (ipsilateral: 100%, cross-over: 40%). Stage of claudication after intervention: I: 85%, IIa: 7%, III: 4%, IV 4%, one amputation. 3-months follow-up: stage I: 86% (n = 24), IIa: 14% (n = 4), one femoro-popliteal bypass. Restenosis rate 18%. 6-months follow-up: stage I: 56% (n = 9), IIa: 31% (n = 5), IIb: 13% (n = 2). Restenosis rate 56%. COMPLICATIONS: 32% (5 perforations, three cases of embolism after PTA, one wire-induced dissection, one retroperitoneal bleeding coming from the puncture site). CONCLUSIONS: The new device is a useful tool for the treatment of (sub)acute long-distance occlusions of the SFA and popliteal artery and in-stent restenosis as well in antegrade technique. Main complications are perforations. Cross-over interventions can only be done in special cases.
Asunto(s)
Arteria Femoral/cirugía , Arteria Poplítea/cirugía , Trombectomía/instrumentación , Trombosis/cirugía , Anciano , Anciano de 80 o más Años , Angiografía , Diseño de Equipo , Femenino , Arteria Femoral/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Arteria Poplítea/diagnóstico por imagen , Recurrencia , Reoperación , Trombosis/diagnóstico por imagenRESUMEN
BACKGROUND: Intracoronary ultrasound (ICUS) has provided insights into vascular pathology and interventional therapy. The Strategy for ICUS-Guided PTCA and Stenting (SIPS) trial tested the hypothesis that routine ICUS guidance of coronary interventions improves outcome. METHODS AND RESULTS: A single-center consecutive-patient randomized design (with 6-month angiographic and 2-year clinical follow-up) was used. Consecutive patients (no chronic total occlusions or emergency procedures) were randomized to ICUS-guided provisional stenting or standard angiographic guidance. Quantitative angiographic minimal lumen diameter (MLD), angiographic restenosis, clinically driven target lesion revascularization, and major adverse cardiac events (MACEs) were evaluated. A total of 291 procedures (356 lesions) were included. Procedure success was higher in the ICUS-guided group than the group randomized to standard guidance (94. 7% versus 87.4%, respectively; P:=0.033), whereas time (65.2+/-31.0 versus 60.5+/-34.0 minutes, P:=0.18) and contrast use (209.3+/-94.1 versus 197.5+/-89.5 mL, P:=0.23) were not significantly different. Stenting rates were similar (49.7% versus 49.5%, P:=0.89). Acute gain was greater in the ICUS-guided group than in the standard guidance group (1.85+/-0.72 versus 1.67+/-0.76 mm, respectively; P:=0.02). Angiographic 6-month analysis revealed no difference in MLD (1.71+/-0.94 versus 1.57+/-0.90, P:=0.19) or binary restenosis rate (>50% diameter stenosis) (29% versus 35%, P:=0.42). Clinical follow-up (602+/-307 days) showed a significant decrease in clinically driven target lesion revascularization in the ICUS group compared with the standard guidance group (17% versus 29%, respectively; P:=0.02). CONCLUSIONS: Although angiographic MLD did not differ significantly after 6 months, ICUS-guided provisional stenting improved 2-year clinical results after intervention.
Asunto(s)
Angioplastia Coronaria con Balón/métodos , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/cirugía , Stents , Angioplastia Coronaria con Balón/efectos adversos , Angiografía Coronaria , Endosonografía , Femenino , Estudios de Seguimiento , Oclusión de Injerto Vascular/diagnóstico , Oclusión de Injerto Vascular/etiología , Humanos , Masculino , Persona de Mediana Edad , Stents/efectos adversos , Tiempo , Resultado del Tratamiento , Grado de Desobstrucción VascularRESUMEN
BACKGROUND: The introduction of an effective antiplatelet therapy with aspirin and ticlopidine after the placement of coronary-artery stents has decreased the risk of thrombotic stent occlusions (TSO) and hemorrhagic complications. However, the use of ticlopidine is limited by hematological and gastrointestinal adverse effects. The safety and efficacy of clopidogrel after stenting remains to be established. METHODS AND RESULTS: After successful coronary stenting during elective or emergency percutaneous transluminal coronary angioplasty, 700 patients with 899 lesions were randomly assigned to receive a 4-week course of either 500 mg ticlopidine (n=345) or 75 mg clopidogrel (n=355), in addition to 100 mg aspirin. All the following clinical events reflecting TSO were included in the prespecified primary cardiac endpoint: cardiac death, urgent target vessel revascularization, angiographically documented TSO, or nonfatal myocardial infarction within 30 days. The primary noncardiac endpoint was defined as noncardiac death, stroke, severe peripheral vascular or hemorrhagic events, or any adverse event resulting in discontinuation of study medication. Cardiac events occurred in 17 patients [11 (3.1%) with clopidogrel and 6 (1.7%) with ticlopidine (P=0.24)]. The primary noncardiac endpoint was observed in 16 patients (4.5%) assigned to receive clopidogrel versus 33 patients (9.6%) assigned to receive ticlopidine (P=0.01). CONCLUSIONS: After the placement of coronary-artery stents in unselected patients, antiplatelet therapy with aspirin and clopidogrel seems to be comparably safe and effective as aspirin and ticlopidine. Noncardiac events were significantly reduced with clopidogrel.
Asunto(s)
Aspirina/administración & dosificación , Trombosis Coronaria/prevención & control , Vasos Coronarios/cirugía , Inhibidores de Agregación Plaquetaria/administración & dosificación , Stents , Ticlopidina/análogos & derivados , Ticlopidina/administración & dosificación , Anciano , Clopidogrel , Quimioterapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/prevención & control , Resultado del TratamientoRESUMEN
PURPOSE: Interval training (INT) is a commonly used method of exercise training in both athletic and clinical populations. Although we generally understand left ventricular (LV) function during steady state (SS) exercise, there are no data regarding LV function during INT. METHODS: We studied eight healthy, physically active volunteers during upright cycle ergometry during 15 min of both SS and INT, at the same average power output (90% individual anaerobic threshold), using first pass radionuclide ventriculography. During INT (60s/60s), measures of LV function were made during work (220 W) after 4 and 12 min and during recovery (120 W) after 7 and 15 min. These were compared with the average of four temporally matched measures made during SS (170 W). RESULTS: During INT, LV ejection fraction increased from rest (67 +/- 6%) to 77 +/- 5, 80 +/- 5, 77 +/- 5 and 79 +/- 4% after 4, 7, 12, and 15 min, respectively. During SS, LV ejection fraction was not significantly different at rest (70 +/- 4%) or during exercise (76 +/- 4, 79 +/- 4, 80 +/- 3, and 81 +/- 3%) after 4, 7, 12, and 15 min, respectively. Other measures of LV function (HR, BP, LV volumes, cardiac output, systemic vascular resistance, peak emptying, and filling rates) were likewise similar during temporally matched measurements during INT and SS. CONCLUSIONS: Although there were the expected transitions of ejection fraction with work and recovery, the overall hemodynamic picture during INT was very similar to SS. These data suggest that LV function during INT is not substantially different to that during SS.
Asunto(s)
Ejercicio Físico/fisiología , Función Ventricular Izquierda , Anciano , Prueba de Esfuerzo , Hemodinámica , Humanos , Ácido Láctico/sangre , Masculino , Persona de Mediana Edad , Ventriculografía con Radionúclidos , Volumen SistólicoRESUMEN
UNLABELLED: The CIS was undertaken with the aim to evaluate the effects of lipid modifications on angiographic progression and regression of CAD in patients with CAD and hypercholesterolemia. The design included a multicenter randomized, double-blind, parallel, placebo-controlled comparison, with target and safety limits for adjusting the trial medication depending on the LDL cholesterol level (LDL-C) achieved, i.e., up to 40 mg of simvastatin (S) or placebo (P) daily, add-on medication (up to 3 x 4 g Colestyramin), and diet counselling. Male patients, average age 49 (< or = 56) years, were included with angiographic CAD and a screening total cholesterol of 207-350 mg/dl, who were not due to undergo coronary bypass surgery or PTCA, who did not suffer from serious other disease (e.g., diabetes mellitus), and who had not undergone coronary bypass surgery previously. RESULTS: All baseline variables were comparable in the treatment groups, with 129 patients taking S and 125 taking P. Of these 254 patients 217 had their final study visit and 207 underwent a second angiography after an average treatment time of 2.3 years under an average daily dose of 37 mg S. 205 pairs of films were available for analysis. Vital information was obtained of all patients until closure of the data bank, half a year after the last study angiography. Five deaths occurred within the study period, 12 through March 15, 1995 (S: 1/6, P: 4/6). 37 patients (S: 18, P: 19) discontinued trial drug and protocol. Concomitant CAD medication was comparable in both groups, except lipid-lowering add-on medication which was significantly higher in the P group (38% versus 13%). Significant changes in lipid levels, on treatment, were observed in the S group amounting to a mean difference in LDL-C of -35%, in Apo-Protein B (ApoB) of -30%, in VLDL-C of -37%, and in triglycerides (TG) of -27%, and in HDL-C of +6%, in comparison to the control group; these differences were even greater in 137 fully compliant patients: -41, -36, -39, -31, and +7%, respectively. Progression in the S group was significantly less, as defined by the two primary target criteria: 1) the minimum obstruction diameter (MOD), determined by quantitative coronary angiography (QCA), decreased about five times less in comparison to the control group (S: by -0.017; P: -0.0954 mm), and 2) the standardized visual global change score (GCS) deteriorated almost three times less in the S group (by +0.20) than in the P group (+0.58). Of the secondary target criteria, the mean lumen diameter (QCA) also developed a significant difference (S: -0.20; P: +0.23 mm; p = 0.0006) with a trend toward regression in the S group. The QCA-%-stenosis deteriorated three- to four-times less in the S group as compared to the control group (S: by 0.69%; P: by 2.73%; p = 0.0022), and the number of patients with angiographic progression was nearly halved (S: 30%; P: 56%; p < 0.0000). These differences were determined by intention to treat analysis (ITT), and they were obtained in spite of lipid lowering add-on medication in 38% of the P patients; they turned out to be more pronounced in 137 fully compliant patients, in an analysis "as treated". The mean decrease in LDL-C serum level caused by S was significantly correlated to the decrease in progression, and multivariate regression analysis of both treatment groups identified LDL-C (or ApoB) and TG as independent predictors of progression. Progression appeared to be most pronounced in low and medium sized lesions, and the beneficial effect of lipid intervention dominated in lesions with 12-56% QCA stenosis severity. A small fraction of patients who suffered from exercise-induced angina, with ST-segment-depression at the beginning of the study, experienced a significant improvement under S as compared to P treatment. Although the study was not designed to show differences in clinical events, the combined number of all major cardiovascular events tended to be less frequent in the S than in the C gr
Asunto(s)
Anticolesterolemiantes/administración & dosificación , Resina de Colestiramina/administración & dosificación , Enfermedad Coronaria/tratamiento farmacológico , Hipercolesterolemia/tratamiento farmacológico , Simvastatina/administración & dosificación , Anticolesterolemiantes/efectos adversos , LDL-Colesterol/sangre , Resina de Colestiramina/efectos adversos , Terapia Combinada , Angiografía Coronaria , Enfermedad Coronaria/sangre , Dieta con Restricción de Grasas , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Esquema de Medicación , Humanos , Hipercolesterolemia/sangre , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Simvastatina/efectos adversosRESUMEN
In coronary heart disease (CHD), pathological myocardial ischemic changes do not always occur with the symptom of heart pain. Methodological problems make it difficult to examine the factors that influence silent and symptomatic myocardial ischemia in everyday life. This study uses a computer-assisted monitoring system with an interactive Holter ECG, an actometer, and an electronic diary. Self-report measurements indicate that symptomatic patients tend toward increased neuroticism, whereas asymptomatic patients engage in beneficial and active coping skills more frequently. The results of the monitoring study demonstrate the same degree of ischemia in silent and symptomatic episodes. However, these episodes show differences in certain psychological context variables. Symptomatic episodes are linked to high subjective strain and severe tension. Because angina pectoris is not a reliable warning signal of myocardial ischemia, the use of the interactive monitoring system is recommended for educating CHD patients on how to cope with excessive strain in everyday life.
Asunto(s)
Electrocardiografía Ambulatoria/psicología , Estilo de Vida , Isquemia Miocárdica/diagnóstico , Isquemia Miocárdica/psicología , Estrés Psicológico/psicología , Adaptación Psicológica , Adulto , Anciano , Angina de Pecho/etiología , Enfermedad Coronaria/complicaciones , Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/psicología , Diagnóstico por Computador/métodos , Electrocardiografía Ambulatoria/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/clasificación , Isquemia Miocárdica/complicaciones , Esfuerzo FísicoRESUMEN
This study sought to assess the safety of interval exercise training in patients with chronic congestive heart failure (CHF) with respect to left ventricular (LV) function. For effective rehabilitation in CHF, both aerobic capacity and muscle strength need to be improved. We have previously demonstrated in both coronary artery bypass surgery and patients with CHF that interval exercise training (IET) offers advantages over steady-state exercise training (SSET). However, because LV function during IET has not yet been studied, the safety of this method in CHF remains unclear. To assess LV function during IET and SSET, at the same average power output, 11 patients with stable CHF were compared with 9 stable coronary patients with minimal LV dysfunction (control group). Using first-pass radionuclide ventriculography, changes in LV function were assessed during work versus recovery phases, at temporally matched times between the fifth and sixteenth minute of IET and SSET. In CHF during IET, there were no significant variations in the parameters measured during work and/or recovery phases. During the course of both IET and SSET, there was a significant increase in LV ejection fraction (5 vs 4 U; p <0.05 each), accompanied by increased heart rate (6 vs 8 beats/min; p <0.05 each) and cardiac output (2.4 vs 1.8 L/min; p <0.01 and p <0.05). In CHF, the magnitude of change in LV ejection fraction during IET was similar to that seen in controls. Both LV ejection fraction and the clinical status in patients with CHF remained stable during IET. Because IET appears to be as safe as SSET with respect to LV function, IET can be recommended for exercise training in CHF to apply higher peripheral exercise stimuli and with no greater LV stress than during SSET.
Asunto(s)
Terapia por Ejercicio , Insuficiencia Cardíaca/fisiopatología , Función Ventricular Izquierda/fisiología , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/rehabilitación , Hemodinámica , Humanos , Masculino , Persona de Mediana Edad , Ventriculografía con Radionúclidos , Volumen SistólicoRESUMEN
BACKGROUND: Modification of AV nodal conduction by means of radiofrequency catheter ablation has become the accepted mode of therapy for patients with symptomatic AV nodal re-entry tachycardias (AVN-RT). The published results demonstrate high success rates and a low incidence of severe complications. However, published series have primarily dealt with relatively young patient populations. Little is known about the efficacy and risks of radiofrequency catheter ablation of AVN-RT in the elderly. METHODS: We retrospectively analysed our data of 404 patients who underwent a catheter ablation therapy for AVN-RT between 1992 and June 1997. Nine patients were excluded from further analysis because of presence of more than one tachycardia mechanism. The ablation procedure was performed at the time of the diagnostic electrophysiologic study. RESULTS: The mean age of 395 patients undergoing catheter ablation for AVN-RT was 52.3 years (19-90 years); 85 patients were 65 years old or older. Compared with the younger subgroup, these elderly patients (mean age 70.4 years) more often had organic heart disease (coronary heart disease with or without myocardial infarction 19.3% versus 2.6%; P < 0.02), more often had syncopes or presyncopes with AVN-RT (43.2% versus 29.8%; P < 0.05), had more hospitalisations and emergency treatments because of their symptoms (56.8% versus 39.5%; P < 0.05) although the cycle length of the induced AVN-RT was significantly shorter in the younger patient group (325 ms versus 368 ms; P < 0.001). Slow pathway ablation was performed in 94% of the young and 82% of the elderly (P < 0.001). In 17.5% of the elderly patients versus 6.5% of the young (P < 0.05) the fast pathway approach was chosen as the first therapy or tried after an unsuccessful approach to the slow pathway. The overall success rate (96.8% in the young and 95.3% in the elderly) and the recurrence rate (5.8% in the elderly versus 4.9% in the young) were similar in both patient groups. There were no differences regarding the total procedure of fluoroscopy time, radiation exposure or the incidence of high-degree AV-block necessitating pacemaker implantation (2.3% in the elderly versus 1.6% in the young). CONCLUSIONS: In patients older than 65 years, AVN-RT may lead to severe, sometimes life-threatening symptoms, despite the fact that the tachycardia is not as fast as in younger patients. Radiofrequency catheter ablation can be performed effectively and safely and should be offered to these patients as first-choice therapy.
Asunto(s)
Ablación por Catéter , Taquicardia por Reentrada en el Nodo Atrioventricular/diagnóstico , Taquicardia por Reentrada en el Nodo Atrioventricular/cirugía , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Fascículo Atrioventricular/fisiopatología , Estimulación Cardíaca Artificial/estadística & datos numéricos , Ablación por Catéter/instrumentación , Ablación por Catéter/métodos , Ablación por Catéter/estadística & datos numéricos , Distribución de Chi-Cuadrado , Electrofisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Taquicardia por Reentrada en el Nodo Atrioventricular/fisiopatologíaRESUMEN
BACKGROUND: In chronic heart failure (CHF), impaired pulmonary function can independently contribute to oxygen desaturation and reduced physical activity. We investigated the effect of breathing rate on oxygen saturation and other respiratory indices. METHODS: Arterial oxygen saturation (SaO2) and respiratory indices were recorded during spontaneous breathing (baseline) and during controlled breathing at 15, six, and three breaths per min in 50 patients with CHF and in 11 healthy volunteers (controls). 15 patients with CHF were randomly allocated 1 month of respiratory training to decrease their respiratory rate to six breaths per min. Respiratory indices were recorded before training, at the end of training, and 1 month after training. FINDINGS: During spontaneous breathing, mean SaO2 was lower in CHF patients than in controls (91-4% [SD 0.4] vs 95.4% [0.2], p<0.001). Controlled breathing increased SaO2 at all breathing rates in patients with CHF. Compared with baseline, minute ventilation increased at 15 breaths per min (+45.9% [9.8], p<0.01), did not change at six breaths per min, and decreased at three breaths per min (-40.3% [4.8], p<0.001). In the nine CHF patients who had 1 month of respiratory training, resting SaO2 increased from 92.5% (0.3) at baseline to 93.2% (0.4) (p<0.05), their breathing rate per min decreased from 13.4 (1.5) to 7.6 (1.9) (p<0.001), peak oxygen consumption increased from 1157 (83) to 1368 (110) L/min (p<0.05), exercise time increased from 583 (29) to 615 (23) min/s (p<0.05), and perception of dyspnoea reduced from a score of 19.0 (0.4) to 17.3 (0.9) on the Borg scale (p<0.05). There were no changes in the respiratory indices in the patients who did not have respiratory training. INTERPRETATION: Slowing respiratory rate reduces dyspnoea and improves both resting pulmonary gas exchange and exercise performance in patients with CHF.
Asunto(s)
Insuficiencia Cardíaca/fisiopatología , Oxígeno/sangre , Respiración , Disnea/fisiopatología , Prueba de Esfuerzo , Femenino , Insuficiencia Cardíaca/sangre , Insuficiencia Cardíaca/terapia , Humanos , Masculino , Persona de Mediana Edad , Intercambio Gaseoso Pulmonar , Terapia Respiratoria , Relación Ventilacion-PerfusiónRESUMEN
PURPOSE: Kinetics of VO2 at onset of constant work rate exercise was previously shown to be slowed in patients with chronic heart failure (CHF) compared with that in healthy normals. Because bicycle ergometry with ramp protocol is usually used for exercise testing with CHF patients, it would be of practical importance if it can be shown that a delay in the time interval of linear increase of VO2 (TILIV) to work rate occurs after beginning ramp exercise. Data of central hemodynamics (CHF) and noninvasive cardiopulmonary parameters (CHF, normals) should also correlate with VO2 delay time if this parameter is related to cardiopulmonary exercise capacity. METHODS: Fifteen males with CHF (mean +/- SEM: age 52 +/- 2 yr; ejection fraction 32 +/- 4%; peak cardiac index 3.9 +/- 0.3 L x m(-2) x min(-1)) and 28 healthy males (50 +/- 1 yr) were assessed. During ramp bicycle ergometry (3 min unloaded, work rate increments of 12.5 W x min(-1)), VO2 was measured breath by breath. RESULTS: After the onset of ramp exercise, there was a difference in the TILIV between patients and normals (83.7 +/- 3.6 vs 66.8 +/- 2.9 s; P < 0.001). Significant differences between both groups were also found for VO2 at ventilatory threshold (VT) (10.1 +/- 0.1 vs 15.2 +/- 0.7 mL x kg(-1) x min(-1); P < 0.0001), VO2 at VT relative to predicted VT (58 +/- 4 vs 97 +/- 4%; P < 0.0001), peak VO2 (13.2 +/- 1.0 vs 34 +/- 1.4 mL x kg(-1) x min(-1), P < 0.001), and increase of systolic blood pressure (36 +/- 7 vs 71 +/- 5 mm Hg; P < 0.0001). In CHF, the TILIV correlated significantly with peak cardiac index and VO2 at VT (r = -0.71; P < 0.005 each), relative value of VO2/kg at VT (r = -0.61; P < 0.03), peak VO2/kg (r = -0.63; P < 0.01), and increase of systolic blood pressure (r = -0.52; P < 0.02). In the normals only VO2/kg at VT correlated significantly with TILIV (r = -0.41; P < 0.03). In patients, stepwise regression analysis identified three predictors which could explain 79% of the variance of TILIV: VO2/kg at VT (r2 = 0.51), peak cardiac index (r2 = 0.20), and peak VO2/kg (r2 = 0.08). CONCLUSION: TILIV, determined at the onset of ramp exercise, is prolonged in CHF patients compared with that in normals and reflects severity of functional impairment because of reduced cardiac index and aerobic capacity. TILIV can provide information about changes in cardiopulmonary exercise capacity and thus can be used for follow-up and treatment studies in CHF.
Asunto(s)
Gasto Cardíaco Bajo/fisiopatología , Ejercicio Físico/fisiología , Consumo de Oxígeno , Prueba de Esfuerzo , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia , Factores de TiempoRESUMEN
Standardized guidelines for exercise training for patients with chronic congestive heart failure (CHF) have not been established. In the past, CHF patients involved in exercise training studies demonstrated a wide range of cardiac and functional impairment, with an ejection fraction between 18 and 35% and a peak VO2 between 12.2 and 25.4 ml/kg/min on average. For determination of training intensity, a VO2 between 40 and 70% of peak VO2 and/or training heart rate between 60 and 80% of peak heart rate was used. There was also a wide range for frequency (between 3 and 7 times per week) and duration of training (between 20 and 60 min per session). For aerobic exercise training only continuous training methods were applied. We have developed a new interval training method which allows intense exercise stimuli on peripheral muscles with minimal cardiac strain. After only three weeks of training, the improvement in aerobic capacity was similar to that reported after longer training periods using continuous methods. To determine work rate for work phases of interval training, a special steep ramp test was developed. By analysis of acute physical responses to this testing procedure and to the interval training, both were proven to be tolerable in CHF patients, even if their ejection fraction is as low as 13%, or peak cardiac index not greater than 1.61/m2/min, and peak VO2 less than 8.5 ml/kg/min.
Asunto(s)
Ejercicio Físico , Insuficiencia Cardíaca/rehabilitación , Educación y Entrenamiento Físico/métodos , Enfermedad Crónica , Terapia por Ejercicio , Insuficiencia Cardíaca/fisiopatología , Frecuencia Cardíaca , Hemodinámica , Humanos , Volumen SistólicoRESUMEN
We prospectively assessed whether baseline central hemodynamics and exercise capacity can predict improvement of VO2 at ventilatory threshold (VT) after exercise training in patients with severe chronic congestive heart failure. Eighteen patients (mean +/- SEM; age 52 +/- 2 years), half of them listed for transplant, underwent 3 weeks of exercise training (interval cycle and treadmill walking; 5 x/week) and 3 weeks of activity restriction in a random-order crossover trial. Baseline data were not significantly different for groups with exercise training first and activity restriction first: cardiac index at rest (2.1 +/- 0.1 L/m2/min), maximum cardiac index (3.1 +/- 0.2 L/m2/min) (Fick), and echocardiographic ejection fraction (21 +/- 1%). The same was true for cardiopulmonary exercise data (cycle ergometry; up 12.5 W/min): VO2 at VT (9.3 +/- 0.4 ml/kg/min), maximum VO2 (12.2 +/- 0.7 ml/kg/min), VT in percentage of predicted maximum VO2 (31 +/- 2%), heart rate at VT (95 +/- 4 beats/min), and decrease of dead space-to-tidal volume ratio from rest to VT (33 +/- 1 --> 29 +/- 1). Improvement of VO2 at VT after training (2.2 +/- 0.4 ml/kg/min; p <0.001) was not related to baseline central hemodynamics (r = <0.10 for each), but was greater in patients with a lower baseline VO2 at VT (r = -0.65; p <0.01), peak VO2 (r = -0.66; p <0.01), VT in percentage of predicted maximum VO2 (r = -0.74; p <0.001), heart rate at VT (r = -0.63; p <0.01), and smaller decrease of dead space-to-tidal volume ratio from rest to VT (r = 0.65; p <0.01). Ejection fraction after exercise training (24 +/- 2%) and activity restriction (23 +/- 2%) did not differ significantly compared with baseline, and patient status (heart failure and cardiac rhythm) remained stable. Three parameters accounted for 84% of the variance of improvement in VO2 at VT: VO2 at VT in percent predicted maximum VO2, decrease of dead space-to-tidal volume ratio, and heart rate at VT. The findings suggest that there was a greater increase in VO2 at VT after exercise training in patients with greater peripheral deconditioning at baseline. The improvement was unrelated to central hemodynamics. Clinically stable patients with severe chronic congestive heart failure, potential heart transplant candidates, and those awaiting transplantation may benefit from involvement in a short-term exercise training program.
Asunto(s)
Ejercicio Físico/fisiología , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/rehabilitación , Hemodinámica/fisiología , Prueba de Esfuerzo , Terapia por Ejercicio , Humanos , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Estudios Prospectivos , Análisis de Regresión , Volumen SistólicoRESUMEN
Eleven men with severe chronic heart failure (peak cardiac index 4.0 +/- 0.2 L/m2/min), six on a heart transplantation waiting list, were prospectively assessed. To determine reproducibility of cardiopulmonary and hemodynamic variables for clinical purposes during ramp bicycle ergometry, the patients underwent two ramp bicycle ergometer tests (3 minutes unloaded, work rate increments of 12.5 W/min) with a 1-week interval between tests. Oxygen uptake (VO2) carbon dioxide production (VCO2), and ventilation were measured breath by breath, and calculations were performed to determine gas exchange ratio, oxygen pulse, ventilatory equivalents of oxygen and carbon dioxide, and end-tidal partial pressure for oxygen and carbon dioxide. Additionally, heart rate, blood pressure, and lactate levels were assessed. Measurements were performed at submaximum work rate levels of 25 W, 50 W, and 75 W at ventilatory threshold and at peak work rate. At all measurement points, the coefficient of variation for cardiopulmonary variables was between 1.4% and 7.1% for submaximum work rate levels, between 1.2% and 4.4% at ventilatory threshold, and between 2.4% and 7.1% at peak work rate. For heart rate, blood pressure, and lactate levels, coefficient of variation was between 2.7% and 5.7% for submaximum work rate levels, between 1.4% and 6.1% at ventilatory threshold, and between 1.2% and 5.5% at peak work rate. The data suggest high reproducibility for duplicate measurements of cardiopulmonary and hemodynamic variables during ramp bicycle ergometry in patients with severe chronic heart failure. The results may be used to determine whether any variable in a single patient is significantly different from that obtained in a previous exercise test or if the change is within experimental error.
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Insuficiencia Cardíaca/fisiopatología , Corazón/fisiopatología , Pulmón/fisiopatología , Esfuerzo Físico/fisiología , Umbral Anaerobio , Presión Sanguínea/fisiología , Dióxido de Carbono/sangre , Dióxido de Carbono/metabolismo , Gasto Cardíaco/fisiología , Enfermedad Crónica , Ergometría , Prueba de Esfuerzo , Frecuencia Cardíaca/fisiología , Trasplante de Corazón , Hemodinámica/fisiología , Humanos , Lactatos/sangre , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Consumo de Oxígeno/fisiología , Presión Parcial , Estudios Prospectivos , Intercambio Gaseoso Pulmonar/fisiología , Reproducibilidad de los Resultados , Respiración/fisiología , Volumen de Ventilación Pulmonar , Factores de Tiempo , Listas de Espera , TrabajoRESUMEN
We evaluated the use of both intracoronary ultrasound (ICUS) information and unique balloon characteristics provided by a combined ICUS/variable diameter balloon catheter during coronary interventions to achieve the maximal residual lumen using the least number of devices. In 47 patients, 64 coronary lesions were treated with either sequential percutaneous transluminal coronary angioplasty (PTCA) (n = 40) or stenting (primary [n = 17], secondary [n = 7]). The result after PTCA was judged satisfactory if the lumen cross sectional area (by ICUS) in the lesion exceeded 65% of the mean reference area. Stent implantation was judged according to revised MUSIC trial criteria. PTCA or stenting was successful in all 64 lesions using 47 combination devices and 10 conventional balloons (mean number of balloons per lesion: 0.90). PTCA group: diameter stenosis decreased from 78 +/- 11 to 23 +/- 13% following inflation at 10.3 +/- 3.0 atm. ICUS lumen area was 4.6 +/- 1.9 mm2 (proximal reference: 7.4 +/- 3.3 mm2, distal reference: 5.7 +/- 1.8 mm2) resulting in a residual area stenosis of 28 +/- 15%. Stent group: diameter stenosis was reduced from 77 +/- 14 to 10 +/- 10% after stenting. ICUS defined minimal lumen area in the stent was 8.2 +/- 2.2 mm2 (proximal reference: 8.7 +/- 2.6 mm2, distal reference: 8.0 +/- 2.2 mm2) resulting in a residual area stenosis of 7.2 +/- 14.6%. No patient death, myocardial infarction, or emergency surgery occurred and only one target lesion required re-PTCA during hospitalization. In conclusion, use of a combined ICUS/variable diameter balloon catheter allows a single device strategy for ICUS-guided PTCA and stenting in the majority (84%) of unselected lesions.
Asunto(s)
Angioplastia Coronaria con Balón/métodos , Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/terapia , Stents , Adulto , Anciano , Angioplastia Coronaria con Balón/instrumentación , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ultrasonografía IntervencionalRESUMEN
Eighteen hospitalized patients with severe chronic heart failure (ejection fraction [mean +/- SEM] 21% +/- 1%) underwent 3 weeks of exercise training (interval bicycle ergometer and treadmill walking training exercises) and 3 weeks of activity restriction in a random-order crossover trial. Before and after exercise training and after activity restriction, a 6-minute walking test was performed to determine the maximum distance walked, hemodynamic and cardiopulmonary responses, norepinephrine levels, and ratings of leg fatigue and dyspnea while walking. A ramp test on bicycle ergometer (increments of 12.5 W/min) was performed before and after exercise training and activity restriction to determine peak oxygen uptake. After training, the maximum distance walked was increased by 65% (from 232 +/- 21 m at baseline to 382 +/- 20 m; p < 0.001), whereas after activity restriction (253 +/- 19 m) there was no significant difference compared with baseline. No significant differences in hemodynamic and cardiopulmonary parameters (with the exception of the ventilatory equivalent for carbon dioxide and perceived exertion) or norepinephrine levels were observed during walking tests. Improvement in maximum distance walked correlated significantly with training-induced increase in peak oxygen uptake measured during bicycle ergometry (r = 0.47, p < 0.05). The lower the maximum distance walked at baseline, the more pronounced the training-induced prolongation of maximum distance (r= -0.73; p < 0.001). These data support the value of exercise training in patients with severe chronic heart failure for improving maximum distance walked, as documented by the 6-minute walking test. The impairment of walking test performance during activity restriction suggests a need for long-term exercise training programs.
Asunto(s)
Terapia por Ejercicio , Tolerancia al Ejercicio/fisiología , Insuficiencia Cardíaca/rehabilitación , Actividades Cotidianas , Estudios Cruzados , Prueba de Esfuerzo , Insuficiencia Cardíaca/fisiopatología , Hemodinámica/fisiología , Humanos , Masculino , Persona de Mediana Edad , Factores de TiempoRESUMEN
This study analyzes a new exercise training procedure, which includes interval exercise training on cycle ergometer (IntCT) (30-s work phases/60-s recovery phases) and on treadmill (60-s work and recovery phases each). Training was applied for 3 wk in 18 patients with severe chronic heart failure (CHF) ((mean +/- SEM) age 52 +/- 2 yr, ejection fraction 21 +/- 1%). Peak VO2 was increased from 12.2 +/- 0.7 to 14.6 +/- 0.7 ml-kg-1 min-1 owing to training (P < 0.001). A specific steep ramp test (work rate increments 25 W.10 s-1) was developed to derive exercise intensity for work phases in IntCT, which was 50% of the maximum work rate achieved. Steep ramp test was performed at the start of the study to determine the initial training work rate, then weekly to readjust it. Since the maximum work rate achieved from this test increased weekly (144 +/- 10 W -->172 +/- 10 W-->200 +/- 11 W; P < 0.001), the training work rate also increased (72 +/- 4 W-->86 +/- 6 W-->100 +/- 7 W; P < 0.001). Physical responses to IntCT were measured. There was no significant change in heart rate, blood pressure, and ratings of perceived exertion (RPE) using a Borg Scale between the first and the third week of training (heart rate 88 +/- 3 b.min-1; blood pressure 115 +/- 4/80 +/- 2 mm Hg; leg fatigue 12 +/- 1; dyspnea 10 +/- 1). Mean lactate concentration (1.70 +/- 0.09 mmol-1-1) indicated an overall aerobic range of training intensity. When compared with the commonly used intensity level of 75% peak VO2 from an ordinary ramp test (work rate increments 12.5 W.min-1), the performed training work rate was more than doubled (240%; P < 0.0001) while cardiac stress was lower (86%; P < 0.01). Values of norepinephrine and epinephrine as well as of RPE corresponded to those measured at 75% peak VO2. Interval exercise training is thus recommended for selected patients with CHF as it allows intense exercise stimuli on peripheral muscles with minimal cardiac strain. Using a steep ramp test, training work rate can be determined and readjusted weekly during initial training period.