[Value of coronary blood flow pattern as a predictor of functional recovery and short-term left ventricular remodeling after primary coronary angioplasty. A transthoracic Doppler study]. / Valor del patrón de flujo coronario tras angioplastia primaria como predictor de recuperación funcional y remodelado ventricular a corto plazo. Estudio mediante ecocardiografía Doppler transtorácica.

INTRODUCTION AND OBJECTIVES: Coronary blood flow measurement using a Doppler guidewire is the most sensitive way of detecting the no-reflow phenomenon following reperfusion of a myocardial infarction (MI). New high-frequency Doppler probes enable coronary blood flow velocity to be measured noninvasively. Our aims were to study the different patterns of left anterior coronary artery blood flow observed by transthoracic Doppler echocardiography, and to describe their association with functional recovery following reperfusion of an anterior MI. METHODS: The study included 57 patients with a mean age of 60 years (range 30-85 years). An abnormal coronary blo:d flow pattern was defined as one in which there was a high peak diastolic velocity and a short deceleration time (i.e., < or = 500 ms). We compared the regional contractility, ventricular volumes, and left ventricular ejection fraction (LVEF) measured after 72 hours with those measured 1 month after MI. RESULTS: Overall, 31 patients (54%) had a normal coronary blood flow pattern (Group 1) and 26 (46%), an abnormal pattern (Group 2). After one month, regional contractility improved in Group-1 patients, as did LVEF, from 46.8 (8.6) to 52.6 (8.8)% (P=.002). In these patients, left ventricular volumes were unchanged. In contrast, regional contractility and LVEF remained unchanged in Group-2 patients whereas ventricular volumes increased, from 55.8 (12.9) to 62.9 (16.8) ml/m2 (P=.05), and from 32.2 (9.5) to 37.1 (14.9) ml/m2 (P< .05). Coronary blood flow pattern was the most important independent predictor of left ventricular remodeling, odds ratio =6.14 (95% CI, 1.56-24.17). CONCLUSIONS: Transthoracic Doppler echocardiographic assessment of coronary blood flow following reperfusion of an anterior myocardial infarction can be used to identify patients with microvascular damage who are progressing towards ventricular dilatation without recovery of myocardial function.

[Dobutamine stress echocardiography in patients with stable chronic angina and a low- or medium-risk on exercise testing: usefulness for assessing long-term prognosis]. / Ecocardiografía con dobutamina en pacientes con angina crónica estable y ergometría de riesgo bajo o intermedio: utilidad en la valoración del pronóstico a largo plazo.

INTRODUCTION AND OBJECTIVES: The ability of stress echocardiography to provide prognostic information that supplements that obtainable from clinical data and exercise electrocardiography is still controversial. Our aim was to determine whether dobutamine stress echocardiography provides additional information on long-term prognosis after conventional exercise testing has indicated that a patient with chronic stable angina has a low or intermediate risk of a cardiac event. PATIENTS AND METHOD: The study included consecutive patients with stable angina who were not found to be at high risk on a previous exercise test. All patients underwent dobutamine stress echocardiography. The mean follow- up period was 4.5+/-1.76 years. The single combined end-point was defined as death due to cardiac disease, nonfatal myocardial infarction, or hospitalization for unstable angina. Multivariate analysis was used to identify independent predictors of cardiac events. RESULTS: There were 24 (19%) cardiac events in the 124 participants: four deaths due to cardiac disease, 10 nonfatal myocardial infarctions, and 10 hospitalizations for unstable angina. Associations were found between a higher event rate during follow-up and previous myocardial infarction, Duke treadmill score, and the detection of regional wall motion abnormalities indicative of multivessel disease by stress echocardiography. CONCLUSIONS: In patients with stable angina who have undergone an exercise test that indicates that they have a low or intermediate risk of cardiac events, dobutamine stress echocardiography provides additional prognostic information to that obtainable from clinical data and exercise testing.

Noninvasive assessment of coronary flow velocity reserve in left anterior descending artery adds diagnostic value to both clinical variables and dobutamine echocardiography: a study based on clinical practice.

AIMS: Our objective was to evaluate, in clinical practice, whether noninvasive assessment of coronary flow velocity reserve in left anterior coronary artery adds diagnostic information to both clinical variables and wall motion abnormalities derived from dobutamine stress echocardiography. METHODS AND RESULTS: We studied 130 patients who were scheduled for coronary angiography after undergoing dobutamine stress echocardiography. The same day, flow in left anterior descending artery was detected by transthoracic Doppler echocardiography. A Doppler signal of left anterior descending artery was detected in 110 patients (85%). We identified significant left anterior descending artery stenosis (>50% diameter stenosis) in 42 patients. Sensitivity and specificity of abnormal coronary flow velocity reserve (<2) to detect left anterior descending artery stenosis were 86% and 57%, respectively. Wall motion abnormalities had a sensitivity and specificity of 52% and 82%. After forcing the clinical and dobutamine stress echo variables into a regression model with three modeling steps, an abnormal coronary flow velocity reserve provided incremental information in predicting significant left anterior descending artery stenosis. CONCLUSION: An abnormal coronary flow velocity reserve by transthoracic Doppler echocardiography adds diagnostic value to both clinical data and variables derived from dobutamine stress echo to detect significant left anterior descending artery stenosis.

[Functional assessment of patients with hypertrophic cardiomyopathy by maximal oxygen consumption]. / Evaluación funcional de los pacientes con miocardiopatía hipertrófica mediante análisis del consumo de oxígeno máximo.

INTRODUCTION AND OBJECTIVES: Differences between anatomical severity and clinical manifestations are frequent in patients with hypertrophic cardiomyopathy. Our objective was to assess functional capacity in a consecutive group of patients with hypertrophic cardiomyopathy measuring exercise aerobic parameters, as well as clinical and echocardiographic variables. PATIENTS AND METHOD: We studied 98 consecutive patients with hypertrophic cardiomyopathy. All patients underwent both echocardiographic and cardiopulmonary exercise testing. The control group consisted of 22 untrained persons. We studied exercise capacity by analyzing maximal oxygen consumption and aerobic functional capacity, among other variables. RESULTS: Patients with hypertrophic cardiomyopathy attained significantly lower maximal oxygen consumption values than controls (24.1 5.9 vs 36.4 5.9 ml/kg/min; p = 0.0001). Maximal aerobic capacity was significantly different among patients with NYHA functional capacity class I, II or III (78.9 13.5%; 71.9 14.7%; 63.9 15.7%; p = 0.009). However, considerable overlap was found between groups in maximal aerobic capacity. Functional impairment was greater in patients with left ventricular thickness > 20 mm, ejection fraction < 50%, left atrial dimension > 45 mm and pseudonormal or restrictive transmitral flow pattern. CONCLUSIONS: Patients with hypertrophic cardiomyopathy show significant functional impairment, which is difficult to detect from their clinical manifestations. Optimal assessment requires cardiopulmonary exercise testing.

[Detection of angiographic lesions in the left anterior descending coronary artery by transthoracic Doppler echocardiography: usefulness of non-invasive assessment of coronary flow reserve]. / Detección de estenosis angiográfica de la arteria coronaria descendente anterior mediante ecocardiografía Doppler transtorácica: utilidad de la medida no invasiva de la reserva del flujo coronario.

INTRODUCTION: We evaluated the feasibility of detecting blood flow in the left anterior descending coronary artery and the usefulness of measuring coronary flow reserve to diagnose significant coronary artery disease, both by means of transthoracic Doppler echocardiography using a high-frequency transducer and echo-contrast agent. PATIENTS AND METHOD: We studied 107 patients who were scheduled for coronary arteriography for known or suspected ischemic heart disease. A Doppler signal was recorded by a pulsed wave in the distal left anterior descending artery at baseline and after dipyridamole infusion. An echo-contrast agent was administered to all patients. A coronary flow reserve equal to or higher than 1.7 was considered normal. RESULTS: We recorded Doppler signals in the left anterior descending coronary artery of 83 patients (78%). Significant stenosis of the left anterior descending coronary artery was observed in 24 out of 83 patients (29%). The prevalence of significant stenosis was higher (62 vs 29%; p = 0.006) in patients in which no Doppler signal was detected. The sensitivity, specificity, and accuracy of abnormal coronary flow reserve in detecting significant stenosis of the left anterior descending coronary artery were 87, 74 and 78%, respectively. CONCLUSIONS: The measurement of coronary flow reserve by transthoracic Doppler echocardiography using a high-frequency transducer and echo-contrast agent is a feasible, widely available, and accurate method for detecting significant stenosis of the left anterior descending coronary artery.

Prognosis of patients with unstable angina and low-risk exercise test: significance of ST-segment depression on the admission ECG.

The presence of ST-segment depression on the admission electrocardiogram (ECG) is an important predictor of poor outcome in patients with unstable angina. On the other hand, patients with unstable angina who undergo a low-risk exercise test are supposed to have a favorable prognosis. The objective of the study was to determine the prognostic significance of ST-segment depression on the admission ECG in patients with unstable angina who undergo an exercise test that indicates a low risk of events. An interpretable exercise test was performed in 257 patients with primary unstable angina. A low-risk exercise test was completed by 156 (60%) patients and medical therapy was planned for all these patients. A multivariate analysis was performed in order to determine the independent predictors of events (cardiac death, nonfatal acute myocardial infarction, or admission for unstable angina) during a 12-month follow-up. Among patients with a low-risk exercise test, there were no significant differences between patients with and without ST-segment depression on the presenting ECG with regard to event rate (34 vs. 29%, P=NS). In multivariate analysis, ST-segment depression was not related to a higher incidence of events. Our findings appear to indicate that the presence of ST-segment depression on the admission ECG loses its prognostic significance in patients with primary unstable angina if they complete a low-risk exercise test.