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1.
Pacing Clin Electrophysiol ; 22(9): 1407-9, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10527026

RESUMEN

Two cases of malpositioned LV electrodes are presented. Transesophageal echocardiography (TEE) allowed for a careful inspection of left-sided leads and for tracking their course. One LV and two right-sided leads were safely retrieved with TEE monitoring. One chronic LV lead was left in place as it was heavily fibrosed. TEE was helpful in the inspection and monitoring of the extraction and also in guided traction efforts. This is the first published report of echocardiographic visualization of the lead retrieval procedure.


Asunto(s)
Remoción de Dispositivos/métodos , Ecocardiografía Transesofágica , Electrodos Implantados/efectos adversos , Marcapaso Artificial/efectos adversos , Adulto , Anciano , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Humanos , Masculino
2.
Pacing Clin Electrophysiol ; 20(11): 2867-9, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9392821

RESUMEN

Initial treatment of atrial fibrillation often involves pharmacological therapy to control ventricular response. While verapamil is usually safe and effective when used for this purpose, we report a proarrhythmic response. In this report a 30-year-old female presented with palpitations associated with atrial fibrillation and a ventricular response of 145 beats/min. Soon after she was given 5 mg of intravenous verapamil her ECG documented a regular wide QRS tachycardia at 290 beats/min. After 7 seconds the rhythm returned to an irregularly irregular narrow QRS tachycardia at 125-150 beats/min. At a later electrophysiology study there was neither evidence of preexcitation nor inducible supraventricular or ventricular tachycardia. These data suggest that verapamil may have been associated with acceleration of the heart rate. The mechanism of proarrhythmia may be related to an alteration in the atrial rhythm from atrial fibrillation to atrial flutter, with additional factors as well.


Asunto(s)
Antiarrítmicos/efectos adversos , Fibrilación Atrial/tratamiento farmacológico , Aleteo Atrial/inducido químicamente , Frecuencia Cardíaca/efectos de los fármacos , Verapamilo/efectos adversos , Adulto , Antiarrítmicos/administración & dosificación , Antiarrítmicos/uso terapéutico , Electrocardiografía , Femenino , Humanos , Inyecciones Intravenosas , Verapamilo/administración & dosificación , Verapamilo/uso terapéutico
3.
Biofizika ; 42(3): 558-66, 1997.
Artículo en Ruso | MEDLINE | ID: mdl-9296616

RESUMEN

The method of investigation of dynamic correlation functions in molecules with conformational mobility on an example of modified dypeptides by molecular dynamics is proposed. Comparison of results for different types torsion angles and internuclear distances are carried out. Connection between the chemical structure of peptides and the peculiarities of internal dynamic correlations is established. A question about dynamic isomorphism of amino acids is discussed.


Asunto(s)
Dipéptidos/química , Conformación Proteica , Modelos Moleculares
4.
Biofizika ; 42(1): 47-53, 1997.
Artículo en Ruso | MEDLINE | ID: mdl-9181801

RESUMEN

The method of molecular dynamics investigations of the particularities of macromolecule physical-chemical properties is discussed. The results, obtained from the calculations of modified dipeptides in different regimes (different temperatures, length of trajectories and ways of thermostat simulation) are compared. The optimal conditions for this peptides calculations are determined: collisional dynamics regime, trajectories not less than 5000 ps, temperature about 1000 K. In this case the figurative point is able to scan the molecule configuration space and the statistically reliable results could be obtained.


Asunto(s)
Dipéptidos/química , Conformación Proteica , Calor
6.
Am Heart J ; 131(1): 51-8, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8554019

RESUMEN

To further define the relation between changing adrenergic tone, beta-blocker therapy, and clinical ventricular tachycardia (VT), we evaluated these factors in 35 patients with VT unrelated to coronary artery disease or ventricular dysfunction. Testing included Holter monitoring (91% had VT), exercise test (69% had VT), Adrenergic responsiveness of VT was graded according to diurnal variation, response to exercise, isoproterenol infusion, and response to beta-blockers. beta-Blockers were effective and well tolerated in this population. There was also a predictable relation between changing adrenergic tone and the arrhythmia response to beta-blocker therapy.


Asunto(s)
Fibras Adrenérgicas/efectos de los fármacos , Antagonistas Adrenérgicos beta/uso terapéutico , Sistema de Conducción Cardíaco/efectos de los fármacos , Taquicardia Ventricular/tratamiento farmacológico , Adolescente , Fibras Adrenérgicas/fisiología , Agonistas Adrenérgicos beta/uso terapéutico , Adulto , Anciano , Ritmo Circadiano , Estimulación Eléctrica , Electrocardiografía Ambulatoria , Prueba de Esfuerzo , Femenino , Estudios de Seguimiento , Corazón/efectos de los fármacos , Corazón/fisiopatología , Sistema de Conducción Cardíaco/fisiopatología , Humanos , Isoproterenol/uso terapéutico , Masculino , Persona de Mediana Edad , Esfuerzo Físico/fisiología , Sueño/fisiología , Simpatomiméticos/uso terapéutico , Taquicardia Ventricular/fisiopatología , Disfunción Ventricular Derecha/tratamiento farmacológico , Disfunción Ventricular Derecha/fisiopatología
7.
Clin Cardiol ; 18(10): 568-72, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8785901

RESUMEN

The signal-average electrocardiogram (SAECG) has been a screening method for identifying patients at risk for ventricular tachycardia (VT) in the setting of coronary artery disease (CAD). Its significance in patients with VT unrelated to CAD or left ventricular dysfunction is undetermined. In order to define the value of SAECG in this patient population further, we compared the time domain SAECG at 25, 40, and 80 Hz filters in 35 patients with clinically symptomatic VT in the absence of structural heart disease was compared with 10 normal controls and 10 patients with CAD and inducible VT. SAECG data in patients without structural heart disease were intermediate between normal controls and patients with CAD. No single or combined SAECG criterion helped to differentiate between patients with inducible and noninducible VT. There was no concordance to other arrhythmia testing. It was concluded that signal-averaged electrocardiography may have little screening value in VT unrelated to CAD or left ventricular dysfunction.


Asunto(s)
Enfermedad Coronaria/complicaciones , Electrocardiografía , Procesamiento de Señales Asistido por Computador , Taquicardia Ventricular/diagnóstico , Disfunción Ventricular Izquierda/complicaciones , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Taquicardia Ventricular/complicaciones , Taquicardia Ventricular/tratamiento farmacológico
10.
J Am Coll Nutr ; 13(2): 127-32, 1994 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8006293

RESUMEN

Many years ago, experimental medicine accumulated substantial evidence that magnesium (Mg) balance was important for a stable cardiovascular system. Recent clinical interest was aroused by evidence of decreased mortality in patients with acute myocardial infarction (AMI), treated with Mg infusions. Pharmacologic actions of Mg include its antiarrhythmic, antivasospastic and other important cardiovascular effects, substantiating the rationale for its use in AMI. Direct pharmacologic effect of this ion, rather than compensation of hypomagnesemia frequently encountered during acute ischemic injury, has been suggested to account for the above benefits. Several trials studied the efficacy of early Mg therapy in decreasing mortality from AMI while most of the data point to improved survival, a few trials could not demonstrate any benefit of Mg. The reported rate of complications with this therapy is low though the potential for serious side effects exists. Larger studies of Mg in AMI are expected to resolve the existing controversy.


Asunto(s)
Arritmias Cardíacas/tratamiento farmacológico , Magnesio/uso terapéutico , Infarto del Miocardio/tratamiento farmacológico , Humanos , Magnesio/administración & dosificación , Magnesio/efectos adversos , Magnesio/farmacología , Magnesio/fisiología
12.
Am Heart J ; 126(6): 1348-56, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8249792

RESUMEN

We studied 41 patients with clinically symptomatic ventricular tachycardia in the absence of coronary artery disease or left ventricular dysfunction to define the extent of right and left heart derangement and their relation to electrophysiologic and clinical data. Individual echocardiographic measurements as well as global assessment scores of the right and left heart demonstrated a wide spectrum of right heart echocardiographic abnormalities. There was much less variation in the left heart, with the majority of patients being close to normal. There was an association between the right heart score, the clinical presentation of arrhythmia, the response to programmed electrical stimulation, and the recurrence of arrhythmia (p < 0.05). Thus echocardiographic findings demonstrate the whole spectrum of right heart involvement in patients with apparent idiopathic ventricular tachycardia and can give insight into clinical history, arrhythmia inducibility, and prognosis.


Asunto(s)
Ventrículos Cardíacos/diagnóstico por imagen , Taquicardia Ventricular/diagnóstico por imagen , Adolescente , Adulto , Anciano , Enfermedad Coronaria , Ecocardiografía Doppler , Electrocardiografía , Femenino , Ventrículos Cardíacos/patología , Ventrículos Cardíacos/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Taquicardia Ventricular/patología , Taquicardia Ventricular/fisiopatología , Función Ventricular Izquierda
13.
Am Heart J ; 126(5): 1113-20, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8237753

RESUMEN

Thirty-seven patients with symptomatic ventricular tachyarrhythmia and no apparent structural heart disease were evaluated with multiple cardiovascular tests to establish the relationship between the results of programmed electric stimulation and other clinical and arrhythmia variables. Of 37 patients, 12 (32%) had inducible sustained ventricular tachycardia. Factors associated with the results of programmed electric stimulation included a history of ventricular tachycardia > or = 30 seconds requiring intervention for termination and global right heart abnormality documented by echocardiography. During treatment for a mean follow-up of 50 months, 29 patients did well, 6 patients had recurrences of major arrhythmia symptoms, 1 was lost to follow-up and 1 had a noncardiac death. Those patients with an adverse outcome were more likely to have inducible ventricular tachycardia. Thus certain clinical and echocardiographic data are associated with the results of programmed electric stimulation, which in turn have important prognostic value in this group of patients. Sustained ventricular tachycardia is unlikely to be induced in patients with no evidence of structural heart disease and clinical nonsustained ventricular tachycardia.


Asunto(s)
Estimulación Cardíaca Artificial , Taquicardia Ventricular/fisiopatología , Adolescente , Adulto , Anciano , Electrocardiografía , Femenino , Estudios de Seguimiento , Cardiopatías/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Taquicardia Ventricular/complicaciones , Taquicardia Ventricular/etiología
14.
Am Heart J ; 124(3): 629-35, 1992 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1514490

RESUMEN

Inducible ventricular tachycardia frequently persists despite solitary class I antiarrhythmic drug therapy. To determine the effect of metoprolol as adjuvant therapy, 19 patients with clinical ventricular tachycardia with baseline inducible sustained monomorphic ventricular tachycardia and persistently inducible ventricular tachycardia despite class I drugs were evaluated. Eight of 19 patients (42%) became noninducible when metoprolol was added to class I drug therapy. Sixteen of 19 patients (84%) were harder to induce or noninducible on a regimen of adjuvant metoprolol therapy. In evaluating the clinical characteristics of the 19 patients, no significant differences were found between patients who were persistently inducible and those rendered noninducible. In evaluating the electrophysiologic characteristics, the group eventually rendered noninducible had a significantly shorter baseline induced cycle length (259 +/- 27 vs 305 +/- 53 msec). Combination class I drug and metoprolol therapy significantly lengthened the ventricular effective refractory period in both groups compared with baseline. The long-term follow-up was excellent in all patients remaining on metoprolol in the noninducible group. Therefore adjuvant metoprolol therapy creates a significant improvement in a number of patients with persistently inducible ventricular tachycardia despite class I drug therapy.


Asunto(s)
Antiarrítmicos/uso terapéutico , Metoprolol/uso terapéutico , Taquicardia/tratamiento farmacológico , Adulto , Anciano , Quimioterapia Combinada , Estimulación Eléctrica , Electrofisiología , Femenino , Estudios de Seguimiento , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Taquicardia/fisiopatología
15.
Kardiologiia ; 29(3): 71-4, 1989 Mar.
Artículo en Ruso | MEDLINE | ID: mdl-2733342

RESUMEN

Combined ultrasound investigation (two-dimensional, contrast, Doppler, Mechocardiography) was performed in 32 patients with acute myocardial infarction (AMI). Echo- and electrocardiographic evidence and clinical symptoms suggested AMI of both ventricles in 22 patients. Ten patients with AMI in the left ventricle only made up the control sample. Right cardiac compartments were probed to verify right-ventricular insufficiency. Right-ventricular involvement was confirmed by autopsy in 6 patients. Clinical signs of right-ventricular AMI were detected in 63.6% of second-group patients, and electrocardiographic signs of the same, in 54.6%. Asynergic areas were detected in right-ventricular wall of 90.5% of patients. In cases of right-ventricular AMI, right compartment section area was increased significantly, while right-ventricular evacuation fraction was as significantly reduced. Doppler echocardiography demonstrated a low right-ventricular rapid filling peak rate, as compared to the respective slow filling rate, an indirect indication of right-ventricular AMI. Combined ultrasound investigation is therefore an effective tool for the diagnosis of right-ventricular AMI and assessment of heart performance.


Asunto(s)
Contracción Miocárdica , Infarto del Miocardio/diagnóstico , Adulto , Anciano , Cardiomiopatía Dilatada/diagnóstico , Cardiomiopatía Dilatada/etiología , Ecocardiografía Doppler , Ventrículos Cardíacos/fisiopatología , Humanos , Persona de Mediana Edad , Infarto del Miocardio/fisiopatología
16.
Kardiologiia ; 28(5): 46-50, 1988 May.
Artículo en Ruso | MEDLINE | ID: mdl-3411858

RESUMEN

Gravitation plasmapheresis (PP) on PF-0.5 fractionator was used in 32 patients with acute myocardial infarction to control blood rheologic disorders. Central hemodynamics and myocardial metabolism were monitored by means of right heart probing and echocardiography. A control group of 7 patients were subjected to "mock PP" with a rheopolyglucin infusion. PP limited manifestations of heart failure, normalized the levels of compounds with high molecular weights which conditioned plasma viscosity, reduced significantly total peripheral and total pulmonary resistance, increased the cardiac index, stroke volume and ejection fraction, and improved regional left-ventricular contractility. Myocardial metabolic studies demonstrated a decline in left-ventricular myocardial ischemia, as evidenced by the arteriovenous difference in lactate levels. It is therefore suggested that PP can be effectively used as part of combined treatment for complicated acute myocardial infarction.


Asunto(s)
Hemodinámica , Infarto del Miocardio/terapia , Miocardio/metabolismo , Plasmaféresis , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/fisiopatología
19.
Kardiologiia ; 26(10): 69-72, 1986 Oct.
Artículo en Ruso | MEDLINE | ID: mdl-3795709

RESUMEN

The practicability of using hydrogen peroxide solutions for contrast echocardiography was examined. The administration of 1-3 ml of 0.2% solution mixed with a drop of the patient's blood, into the cubital or catheterized subclavian vein produced intensive and lasting (up to 2 min) contrast of the right cavities of the heart. Cubital injection of the solution was associated with a more lasting effect, as compared to the subclavian administration. The causes of this difference are yet to be investigated. The contrasting effect was fairly persistent and marked even when concentrations of the hydrogen peroxide solutions were reduced to 0.15 or 0.1%. The rate of administration was not more than 1 ml/s and had no negative effect on the quality of the contrast. No side effects associated with repeated administration of 1-3 ml hydrogen peroxide solution in the above-mentioned concentrations were noted in either of the 20 patients thus examined.


Asunto(s)
Rotura Cardíaca Posinfarto/diagnóstico , Rotura Cardíaca/diagnóstico , Defectos del Tabique Interventricular/diagnóstico , Infarto del Miocardio/diagnóstico , Medios de Contraste , Ecocardiografía/métodos , Humanos , Peróxido de Hidrógeno
20.
Ter Arkh ; 57(4): 59-62, 1985.
Artículo en Ruso | MEDLINE | ID: mdl-4012630

RESUMEN

The authors provide data obtained during echocardiographic examination of 16 patients with different patterns of alcoholic heart injury primarily at the early stages of alcoholism. The group of patients without heart rhythm abnormality showed a decrease in myocardial contractile function, moderate dilatation of the left ventricle and its hypertrophy. In patients with heart rhythm abnormalities, the progress of myocardial lesions, dilatation of the left ventricle, left atrium and right ventricle prevailed over hypertrophy of the left ventricle. Hypertrophy and dilatation of the left ventricle were most pronounced in patients with permanent atrial fibrillation. The disease was discovered to run its course in stages with gradual superimposition on left ventricle hypertrophy and dilatation followed by a decrease in myocardial contractile function.


Asunto(s)
Cardiomiopatía Alcohólica/diagnóstico , Ecocardiografía , Adulto , Anciano , Arritmias Cardíacas/inducido químicamente , Arritmias Cardíacas/diagnóstico , Cardiomiopatía Alcohólica/fisiopatología , Electrocardiografía , Humanos , Persona de Mediana Edad , Contracción Miocárdica/efectos de los fármacos
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