RESUMEN
As structural heart disease interventions continue to evolve to a sophisticated level, accurate and reliable imaging is required for pre-procedural selection of cases, intra-procedural guidance, post-procedural evaluation, and long-term follow-up of patients. Traditionally, cardiovascular procedures in the catheterization laboratory are guided by fluoroscopy and angiography. Advances in echocardiography can overcome most limitations of conventional imaging modalities and provide successful completion of each step of any catheter-based treatment. Echocardiography's unique characteristics rendered it the ideal technique for percutaneous catheter-based procedures. The purpose of this review is to demonstrate the use of the most common and up-to-date echocardiographic techniques in recent non-coronary percutaneous interventional procedures, underlining its inevitable and growing role, as well as illustrating areas of weakness and limitations, and to provide future perspectives.
Asunto(s)
Ecocardiografía/métodos , Cardiopatías/diagnóstico por imagen , Cardiopatías/terapia , Ultrasonografía Intervencional/instrumentación , Angiografía/métodos , Cateterismo Cardíaco/métodos , Ecocardiografía Transesofágica/métodos , Fluoroscopía/métodos , Humanos , Ultrasonografía Intervencional/métodosAsunto(s)
Vasos Coronarios/patología , Stents Liberadores de Fármacos/efectos adversos , Infarto de la Pared Inferior del Miocardio/cirugía , Intervención Coronaria Percutánea/efectos adversos , Paro Sinusal Cardíaco/diagnóstico , Paro Sinusal Cardíaco/etiología , Anciano , Angiografía Coronaria/métodos , Diabetes Mellitus Tipo 2/complicaciones , Femenino , Humanos , Hiperlipidemias/complicaciones , Factores de Riesgo , Factores de TiempoRESUMEN
AIMS: To assess the effect of experimentally induced atrial fibrillation on coronary flow in humans. METHODS AND RESULTS: In 16 patients (10 men, mean age 43+/-13 years) with normal coronary vessels, baseline and hyperaemic blood pressure and Doppler phasic coronary flow velocity were measured, using a 0.014 inch intracoronary Doppler flow wire, during sinus rhythm, experimentally induced atrial fibrillation, and right atrial pacing at a similar heart rate to that during atrial fibrillation. Coronary flow velocity integral per minute increased significantly during both right atrial pacing and atrial fibrillation compared to sinus rhythm, but during right atrial pacing the increase was greater (85+/-43% vs 52+/-25%, P<0.001). This difference persisted even after correction for the product of heart rate and blood pressure (1.15+/-0.51 vs 0.97+/-0.46, respectively, P<0.02). In a further 12 paced patients (seven men, mean age 54+/-10 years) with complete atrioventricular block the induction of atrial fibrillation (atrial fibrillation with regular RR interval) caused no significant changes in coronary flow velocity variables. CONCLUSIONS: Acute atrial fibrillation in humans causes an increase in coronary flow that is, however, insufficient to compensate for the augmented myocardial oxygen demand, mainly because of the irregularity in the ventricular rhythm that exists during atrial fibrillation.
Asunto(s)
Fibrilación Atrial/fisiopatología , Velocidad del Flujo Sanguíneo/fisiología , Circulación Coronaria/fisiología , Enfermedad Aguda , Adenosina/uso terapéutico , Adulto , Amiodarona/uso terapéutico , Antiarrítmicos/uso terapéutico , Fibrilación Atrial/complicaciones , Fibrilación Atrial/tratamiento farmacológico , Función Atrial , Presión Sanguínea/efectos de los fármacos , Femenino , Atrios Cardíacos/efectos de los fármacos , Bloqueo Cardíaco/complicaciones , Bloqueo Cardíaco/tratamiento farmacológico , Bloqueo Cardíaco/fisiopatología , Sistema de Conducción Cardíaco/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Estadística como Asunto , Resistencia Vascular/efectos de los fármacos , Resistencia Vascular/fisiologíaAsunto(s)
Fibrilación Atrial/fisiopatología , Circulación Coronaria , Enfermedad Aguda , Adulto , Femenino , Hemodinámica , Humanos , Masculino , Persona de Mediana EdadRESUMEN
ST-segment deviation was recently described as the only ECG finding that was useful in the diagnosis of acute myocardial infarction during right ventricular pacing. This report shows that the same sign may also indicate the amount of myocardium in jeopardy and the coronary artery responsible.
Asunto(s)
Electrocardiografía , Infarto del Miocardio/diagnóstico , Angioplastia Coronaria con Balón , Angiografía Coronaria , Resultado Fatal , Femenino , Humanos , Persona de Mediana Edad , Infarto del Miocardio/terapia , Marcapaso ArtificialRESUMEN
OBJECTIVES: The purposes of this study were to test the specificity of dipyridamole myocardial perfusion scintigraphy in patients with permanent ventricular pacing (PVP) and to evaluate coronary blood flow and reserve in these patients. BACKGROUND: Permanent ventricular pacing is associated with exercise perfusion defects on myocardial scintigraphy in the absence of coronary artery disease (CAD). On the basis of studies in patients with left bundle brunch block, coronary vasodilation with dipyridamole has been proposed as an alternative to exercise testing for detecting CAD in paced patients, but this approach has never been tested. METHODS: Fourteen patients with a PVP and normal coronary arteries underwent stress thallium-201 scintigraphy and cardiac catheterization. In these patients and in eight control subjects, coronary flow velocities were measured in the left anterior descending coronary artery (LAD) and in the dominant coronary artery before and after adenosine administration. RESULTS: In the paced patients, coronary flow velocities in the LAD and in the dominant coronary artery were significantly lower than those in the control subjects. In addition, seven patients showed perfusion defects on dipyridamole thallium-201 single-photon emission computed tomography, with a specificity of 50% for this test. The defect-related artery in these patients had lower coronary flow reserve (2.6 +/- 0.5) as compared with those without perfusion defects (3.9 +/- 1.0, p < 0.05) or the control group (3.5 +/- 0.5, p < 0.05). CONCLUSIONS: Permanent ventricular pacing is associated with alterations in regional myocardial perfusion. Furthermore, abnormalities of microvascular flow, as indicated by reduced coronary flow reserve in the defect-related artery, are at least partially responsible for the uncertain specificity of dipyridamole myocardial perfusion scintigraphy.
Asunto(s)
Circulación Coronaria/fisiología , Isquemia Miocárdica/diagnóstico por imagen , Marcapaso Artificial , Tomografía Computarizada de Emisión de Fotón Único , Anciano , Velocidad del Flujo Sanguíneo/fisiología , Bloqueo de Rama/diagnóstico por imagen , Bloqueo de Rama/fisiopatología , Bloqueo de Rama/terapia , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/fisiopatología , Diagnóstico Diferencial , Dipiridamol , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Microcirculación/fisiopatología , Persona de Mediana Edad , Isquemia Miocárdica/fisiopatología , Radioisótopos de TalioRESUMEN
BACKGROUND: The presence of atherosclerotic lesions in the thoracic aorta by transesophageal echocardiography (TEE) appears to be a marker for the presence of significant coronary artery disease (CAD) in the general population. HYPOTHESIS: We investigated whether atherosclerotic lesions in the thoracic aorta, by multiplane TEE, could be a marker for CAD in elderly patients. METHODS: In all, 127 patients (67 men, 60 women, aged 68 +/- 13 years), underwent a TEE study with imaging of the thoracic aorta and cardiac catheterization with coronary angiography. The presence of a distinct, linear, or focal, highly echogenic mass protruding into the vessel lumen was the criterion for the diagnosis of atherosclerotic plaque. RESULTS: Atherosclerotic lesions were found in 30 of 36 patients (83.3%) with and in 20 of 91 (22%) without CAD. Of the 41 patients > or = 70 years, atherosclerotic lesions were detected in 14 of 17 (82.3%) with and in 13 of 24 patients (54%) without CAD. The sensitivity, specificity, and positive and negative predictive values in this group were 82.3, 46, 52, and 78.6%, respectively. Multivariate logistic regression analysis revealed that in patients aged > or = 70 years only advanced atherosclerotic lesions were independent predictors of significant CAD. However, the high negative predictive value of the method indicates that the absence of aortic plaque is a strong predictor of the absence of CAD. CONCLUSIONS: The presence of atherosclerotic lesions in the thoracic aorta is a strong predictor of CAD only in patients < 70 years old. However, the negative predictive value of the method is high for all patients regardless of age.
Asunto(s)
Enfermedades de la Aorta/diagnóstico por imagen , Arteriosclerosis/diagnóstico por imagen , Enfermedad Coronaria/diagnóstico por imagen , Ecocardiografía Transesofágica , Anciano , Anciano de 80 o más Años , Aorta Torácica/diagnóstico por imagen , Angiografía Coronaria , Ecocardiografía Transesofágica/instrumentación , Ecocardiografía Transesofágica/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Factores de RiesgoRESUMEN
BACKGROUND: Abnormalities of diastolic function are an important determinant of exercise intolerance in patients with heart failure. However, the relation between left ventricular filling pattern and cardiopulmonary exercise performance has not been adequately studied. METHODS: Thirty-one patients with idiopathic (n = 14) or ischemic (n = 17) dilated cardiomyopathy, demonstrated by coronary angiography, and radionuclide ejection fraction 30.5% +/- 9% underwent cardiopulmonary exercise testing with a modified Naughton protocol and a complete echocardiographic study. Patients were subdivided into restrictive and nonrestrictive groups according to their Doppler transmitral flow pattern. Gas exchange data were measured during exercise testing. The relation of left ventricular filling pattern to cardiopulmonary parameters was assessed in both groups. RESULTS: Exercise duration was similar in the restrictive and nonrestrictive groups but significant differences were found in oxygen consumption (VO(2)) at peak exercise (14.3 +/- 2.4 vs 20.4 +/- 4.7 mL/kg per minute; P <.001) and at the anaerobic threshold (VO(2AT)) (13 +/- 2.2 vs 17.3 +/- 3 mL/kg per minute; P <.001). Simple linear regression analysis revealed that both peak VO(2) and VO(2AT) were significantly correlated with the ratio of peak early (E wave) to late (A wave) transmitral filling velocity, early filling deceleration time, atrial filling fraction, and A-wave velocity but not with left ventricular ejection fraction. Multivariate regression analysis gave only the peak A-wave velocity as an independent predictor for both peak VO(2) and VO(2AT). CONCLUSIONS: In patients with heart failure, abnormalities of diastolic function are the most important determinant of exercise intolerance. A restrictive transmitral flow pattern by Doppler echocardiography is a marker of diminished cardiopulmonary exercise performance in these patients.
Asunto(s)
Cardiomiopatía Dilatada/fisiopatología , Diástole/fisiología , Prueba de Esfuerzo , Insuficiencia Cardíaca/fisiopatología , Disfunción Ventricular Izquierda/fisiopatología , Función Ventricular Izquierda/fisiología , Adulto , Anciano , Umbral Anaerobio/fisiología , Velocidad del Flujo Sanguíneo/fisiología , Presión Sanguínea/fisiología , Gasto Cardíaco/fisiología , Cardiomiopatía Dilatada/diagnóstico , Diagnóstico por Imagen , Femenino , Insuficiencia Cardíaca/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno/fisiología , Intercambio Gaseoso Pulmonar/fisiología , Valores de Referencia , Disfunción Ventricular Izquierda/diagnósticoRESUMEN
A 52-year-old patient underwent percutaneous balloon pericardiotomy because of rapid fluid accumulation. During the procedure, we calculated the amount of blood flow to the nondiseased left anterior descending coronary artery while pericardial pressure was gradually increased by the infusion of warmed normal saline solution. Coronary vasodilator reserve was assessed by intracoronary adenosine. With increasing pericardial pressure, there was a continuous decline in coronary blood flow, due to an increase in coronary vascular resistance, and an unaffected hyperemic response throughout. The maximal hyperemic flow was far less under increased pericardial pressure than at normal pressure, which implies an augmented susceptibility to myocardial ischemia.
Asunto(s)
Taponamiento Cardíaco/fisiopatología , Circulación Coronaria/fisiología , Resistencia Vascular/fisiología , Velocidad del Flujo Sanguíneo/fisiología , Taponamiento Cardíaco/cirugía , Ecocardiografía Doppler , Humanos , Neoplasias Pulmonares/cirugía , Masculino , Persona de Mediana Edad , Pericardiectomía , Pericardiocentesis , ReoperaciónRESUMEN
OBJECTIVES: To investigate the contribution of Doppler-echocardiographically derived aortic indexes of left ventricular systolic function during dipyridamole-stress to the diagnosis of coronary artery disease (CAD). DESIGN: This was a clinical study. METHODS: Echocardiographic studies under baseline and peak dipyridamole stresses were performed on 15 normal subjects and 32 patients with angiographically confirmed CAD. Peak Doppler velocity, acceleration, and acceleration time of the ascending aorta, as well as segmental left ventricular wall motion, were analyzed. RESULTS: The sensitivity, specificity and overall accuracy of wall-motion abnormalities induced by dipyridamole for the detection of CAD were 62.5, 100, and 74.5%, respectively. When wall-motion abnormalities were combined with the percentage changes in peak aortic velocity and acceleration, the overall sensitivities were 84.38 and 78.15%, respectively, the specificities were 66.7 and 80.00%, respectively, and the accuracy was 78.72% for both models. When all three parameters were combined, the sensitivity, specificity and overall accuracy of the method were 87.5, 86.7, and 87.2%, respectively. CONCLUSIONS: Doppler-echocardiographically derived aortic indexes of left ventricular systolic function during dipyridamole stress could be a useful adjunct to two-dimensional echocardiography by improving its sensitivity in the diagnosis of CAD.
Asunto(s)
Enfermedad Coronaria/fisiopatología , Dipiridamol , Ecocardiografía Doppler , Función Ventricular Izquierda/fisiología , Ecocardiografía Doppler/efectos adversos , Ecocardiografía Doppler/métodos , Humanos , Masculino , Persona de Mediana Edad , Volumen Sistólico/fisiologíaRESUMEN
We report the case of a 54-year-old man with pulmonary embolism during convalescence from "idiopathic" pericarditis. A transthoracic echocardiographic examination indicated a large mass within the right atrium. Subsequently, he died from refractory hypotension. On autopsy, two large whitish nodules were found in the right atrium; there was also nodular epicardial infiltration. Both lungs showed multiple, grossly visible tumor emboli with pulmonary infarction and no evidence of conventional thromboembolism. This is the first report of pulmonary tumor embolism due to large cell B-cell primary cardiac lymphoma. Refractory unexplained pericardial effusion, pulmonary embolism without risk factors for venous thrombosis, and/or the existence of a mass in the right heart should arouse clinical suspicion for this rare malignancy.
Asunto(s)
Neoplasias Cardíacas/complicaciones , Linfoma de Células B/complicaciones , Células Neoplásicas Circulantes , Embolia Pulmonar/etiología , Ecocardiografía , Resultado Fatal , Atrios Cardíacos/diagnóstico por imagen , Atrios Cardíacos/patología , Neoplasias Cardíacas/diagnóstico por imagen , Neoplasias Cardíacas/patología , Humanos , Linfoma de Células B/diagnóstico por imagen , Linfoma de Células B/patología , Masculino , Persona de Mediana Edad , Derrame Pericárdico/complicaciones , Derrame Pericárdico/diagnóstico por imagen , Derrame Pericárdico/patología , Embolia Pulmonar/patologíaRESUMEN
OBJECTIVES: The purpose of this study was to determine whether scintigraphic myocardial perfusion defects in patients with left bundle branch block (LBBB) and normal coronary arteries are related to abnormalities in coronary flow velocity pattern and/or coronary flow reserve. BACKGROUND: Septal or anteroseptal defects on exercise myocardial perfusion scintigraphy are common in patients with LBBB and normal coronary arteries. METHODS: Thirteen patients (7 men, age 61+/-8 years) with LBBB and normal coronary arteries underwent stress thallium-201 scintigraphy and cardiac catheterization. In all patients and in 11 control subjects coronary blood flow parameters were calculated from Doppler measurements of flow velocity in the left anterior descending coronary artery (LAD) before and after adenosine administration. RESULTS: The time to maximum peak diastolic flow velocity was significantly longer both for the seven patients with (134+/-19 ms) and for the six without (136+/-7 ms) exercise perfusion defects than for controls (105+/-12 ms, p < 0.05), whereas the acceleration was slower (170+/-54, 186+/-42 and 279+/-96 cm/s2, respectively, p < 0.05). Coronary flow reserve in the patients with exercise perfusion defects (2.7+/-0.3) was significantly lower than in those without (3.7+/-0.5, p < 0.05) or in the control group (3.4+/-0.5, p < 0.05). CONCLUSIONS: Patients with LBBB have an impairment of early diastolic blood flow in the LAD due to an increase in early diastolic compressive resistance resulting from delayed ventricular relaxation. Furthermore, exercise scintigraphic perfusion defects in these patients are associated with a reduced coronary flow reserve, indicating abnormalities of microvascular function in the same vascular territory.
Asunto(s)
Bloqueo de Rama/fisiopatología , Circulación Coronaria , Vasos Coronarios , Adenosina , Anciano , Velocidad del Flujo Sanguíneo/efectos de los fármacos , Bloqueo de Rama/diagnóstico por imagen , Angiografía Coronaria , Circulación Coronaria/efectos de los fármacos , Vasos Coronarios/diagnóstico por imagen , Vasos Coronarios/efectos de los fármacos , Diástole/efectos de los fármacos , Dipiridamol , Ecocardiografía Doppler , Electrocardiografía , Prueba de Esfuerzo , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Tomografía Computarizada de Emisión de Fotón Único , Resistencia Vascular/efectos de los fármacos , VasodilatadoresRESUMEN
The aim of this study was to compare AAIR and DDDR pacing at rest and during exercise. We studied 15 patients (10 men, age 65 +/- 6 years) who had been paced for at least 3 months with activity sensor rate modulated dual chamber pacemakers. All had sick sinus syndrome (SSS) with impaired sinus node chronotropy. The patients underwent a resting echocardiographic evaluation of systolic and diastolic LV function at 60 beats/min during AAIR and DDDR pacing with an AV delay, which ensured complete ventricular activation capture. Cardiac output (CO) was also measured during pacing at 100 beats/min in both pacing modes. Subsequently, the oxygen consumption (VO2AT) and VO2AT pulse at the anaerobic threshold were measured during exercise in AAIR mode and in DDDR mode with an AV delay of 120 ms. The indices of diastolic function showed no significant differences between the two pacing modes, except for patients with a stimulus-R interval > 220 ms, for whom the time velocity integral of LV filling and LV inflow time were significantly lower under AAI than under DDD pacing. At 60 beats/min, CO was higher under AAI than under DDD mode only when the stimulus-R interval was below 220 ms. For stimulus-R intervals longer than 220 ms, and also during pacing at 100 beats/min, the CO was higher in DDD mode. The stimulus-R interval decreased in all patients during exercise. The time to anaerobic threshold, VO2AT, and VO2AT pulse showed no significant differences between the two pacing modes. Our results indicate that, at rest, although AAIR pacing does not improve diastolic function in patients with SSS, it maintains a higher CO than does DDDR pacing in cases where the stimulus-R interval is not excessively prolonged. On exertion, the two pacing modes appear to be equally effective, at least in cases where the stimulus-R interval decreases in AAIR mode.
Asunto(s)
Estimulación Cardíaca Artificial/métodos , Ecocardiografía Doppler , Corazón/fisiopatología , Pulmón/fisiopatología , Síndrome del Seno Enfermo/terapia , Nodo Sinoatrial/fisiopatología , Anciano , Umbral Anaerobio/fisiología , Función del Atrio Izquierdo/fisiología , Gasto Cardíaco/fisiología , Estimulación Cardíaca Artificial/clasificación , Volumen Cardíaco/fisiología , Diástole , Electrocardiografía , Prueba de Esfuerzo , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Consumo de Oxígeno/fisiología , Marcapaso Artificial , Esfuerzo Físico/fisiología , Descanso/fisiología , Síndrome del Seno Enfermo/diagnóstico por imagen , Síndrome del Seno Enfermo/fisiopatología , Nodo Sinoatrial/diagnóstico por imagen , Función Ventricular Izquierda/fisiologíaRESUMEN
A decrease in cardiac parasympathetic tone is a recognized finding in patients with ischemic heart disease, correlating closely with disease severity and overall survival. The aim of this study was to assess whether transdermal scopolamine (Tds), which increases parasympathetic tone in healthy volunteers, increases vagal tone in patients with severe CAD and whether it might have an antiischemic effect. Fifteen patients (10 men, aged 55 +/- 8 years) with three-vessel CAD, but with no prior MI and preserved ventricular function, underwent 24-hour Holter monitoring and exercise testing before and after wearing a scopolamine patch for 24 hours. Time-domain measures of heart rate variability (HRV) and the total number and duration of ischemic episodes were obtained from the Holter recordings for each patient. Tds significantly (P < 0.05) increased the values of all HRV measures. Tds also reduced the total number of ischemic episodes (from 273 to 159, P < 0.05) and their total duration (from 136 to 46 min per patient, P < 0.05). Tds also increased treadmill exercise duration from 293 +/- 101 to 345 +/- 95 seconds (P < 0.05) and the time to 1-mm ST depression from 177 +/- 105 to 244 +/- 128 seconds (P < 0.02), while maximum ST depression was reduced from 2.86 +/- 0.6 to 2.3 +/- 0.3 (P < 0.05). No significant side effects were observed. Tds modifies the autonomic balance in patients with severe CAD toward a condition associated with a better prognosis. It may also be useful as an adjunctive treatment for ischemic heart disease.
Asunto(s)
Enfermedad Coronaria/tratamiento farmacológico , Frecuencia Cardíaca/efectos de los fármacos , Parasimpatolíticos/uso terapéutico , Escopolamina/uso terapéutico , Administración Cutánea , Sistema Nervioso Autónomo/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Quimioterapia Adyuvante , Enfermedad Coronaria/fisiopatología , Progresión de la Enfermedad , Electrocardiografía Ambulatoria , Prueba de Esfuerzo , Tolerancia al Ejercicio , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio , Isquemia Miocárdica/tratamiento farmacológico , Isquemia Miocárdica/etiología , Isquemia Miocárdica/fisiopatología , Sistema Nervioso Parasimpático/efectos de los fármacos , Parasimpatolíticos/administración & dosificación , Pronóstico , Escopolamina/administración & dosificación , Tasa de Supervivencia , Nervio Vago/efectos de los fármacos , Función Ventricular/efectos de los fármacosRESUMEN
In this study the tilt test, in combination with isoproterenol administration, was used to investigate 44 patients with unexplained syncope. The reproducibility of the method was studied in a group of 32 patients who underwent a second test. The administration of isoproterenol during the test increased the sensitivity of the method from 52 to 70% and the reproducibility of a positive result from 61% to 83%, at the expense of a small decrease in specificity (from 100% to 93%). Isoproterenol should thus be considered an essential part of the method, although the low reproducibility of specific types of haemodynamic response limits its value in the choice and the follow up of treatment in individual cases.
Asunto(s)
Cardiotónicos , Isoproterenol , Síncope/diagnóstico , Pruebas de Mesa Inclinada/métodos , Presión Sanguínea , Cardiotónicos/administración & dosificación , Femenino , Frecuencia Cardíaca , Humanos , Infusiones Intravenosas , Isoproterenol/administración & dosificación , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Síncope/etiología , Sistema Vasomotor/fisiopatologíaRESUMEN
INTRODUCTION: Transtelephonic electrocardiographic transmission is a diagnostic technique which has been systematically applied in recent years, mainly for the detection of arrhythmias or pacemaker malfunction. The purpose of this study was to assess the efficacy of this method in the recording and transmission of ST segment and T wave changes. METHOD: A Bruce protocol exercise stress test was carried out in 47 consecutive patients (39 males, eight females, age 53.1 +/- 11.5 years) with suspected coronary artery disease (CAD). At the same time, a transtelephonic ECG system, with a 2-min memory and the capability for 16.5 days continuous recording, was used to transmit the ECG (modified leads II and V5). RESULTS: A positive ST segment shift was observed in 19 patients (40.4%) during the exercise test. The transtelephonic system recorded this change in 18 of these patients but missed the anteroseptal ST segment depression (V2-V4) in one patient (sensitivity 94.7%). All of the 23 patients with no ST segment changes during the exercise test had a negative transtelephonic ECG transmission (specificity 100%). The width of the ST depression recorded from modified lead II on the transtelephonic recording was not significantly different from that of the 12-lead ECG. The same was true for modified lead V5. CONCLUSION: Transtelephonic ECG transmission in patients with suspected CAD can significantly contribute to the investigation of this problem, since the method has high sensitivity and specificity. The capacity for continuous recording and the memory of the device make possible the monitoring of high risk patients for a good length of time.