Kamthorn S. Lee

Prognosis of patients with left ventricular dysfunction, with and without viable myocardium after myocardial infarction. Relative efficacy of medical therapy and revascularization.

BackgroundThe uptake of F-18 deoxyglucose into dysfunction segments after myocardial infarction identifies metabolically active (FDG+) or inactive (FDG−) myocardium. Although patients with FDG+ segments have been found to be at risk for adverse events, the prognostic significance of viable myocardium in relation to other influences on postinfarction prognosis, including revascularization, remain ill defined. The purpose of this study was to investigate the relative prognostic significance of FDG+ tissue and to establish whether myocardial revascularization in patients with viable tissue attenuates the risk of adverse outcome. Methods and ResultsOne hundred thirty-seven patients with left ventricular dysfunction and resting perfusion defects after myocardial infarction underwent positron emission tomography with both dipyridamole stress Rb-82 perfusion imaging and FDG imaging. After the exclusion of 4 patients proceeding to transplantation, 2 with uninterpretable scans and 2 lost to follow-up, 129 patients were followed clinically for 17 ± 9 months. Four groups were defined: patients with FDG+ dysfunctional myocardium who were revascularized (n = 49) or treated medically (n = 21) and those with FDG− segments who were revascularized (n = 19) or treated medically (n = 40). The groups of patients with FDG+ or FDG− findings, with and without revascularization, did not differ with respect to known determinants of postinfarction prognosis: age, left ventricular ejection fraction, or the prevalence of multivessel disease. Nonfatal ischemic events occurred in 48% of medically treated FDG+ patients compared with 8% of revascularized patients with FDG+ tissue (P < .001) and 5% of patients with FDG- myocardium (P < .001). Thirteen patients died from cardiac causes; 11 (85%) had a left ventricular ejection fraction of < 30%, and these patients were evenly distributed between FDG+ and FDG− groups. Using Coxs proportional hazards model, only the presence of FDG+ myocardium (odds ratio, 12.9; P < .001) and the absence of revascularization (odds ratio, 5.8; P = .002) independently predicted ischemic events, while only age (P = .02) and ejection fraction (P < .001) but not the presence of viable myocardium were predictive of death. ConclusionsResidual viable myocardium after myocardial infarction may act as an unstable substrate for further events unless it is revascularized. Despite this association, age and left ventricular dysfunction remained the strongest predictors of cardiac death after myocardial infarction in these patients with a spectrum of left ventricular dysfunction.

Association of chronotropic incompetence with echocardiographic ischemia and prognosis

OBJECTIVES This study sought to examine the prognostic importance of chronotropic incompetence among patients referred for stress echocardiography. BACKGROUND Although chronotropic incompetence has been shown to be predictive of an adverse prognosis, it is not clear if this association is independent of exercise-induced myocardial ischemia. METHODS Consecutive patients (146 men and 85 women; mean age 57 years) who were not taking beta-adrenergic blocking agents and were referred for symptom-limited exercise echocardiography were followed for a mean of 41 months. Chronotropic incompetence was assessed in two ways: (1) failure to achieve 85% of the age-predicted maximum heart rate and (2) a low chronotropic index, a heart rate response measure that accounts for effects of age, resting heart rate and physical fitness. RESULTS The primary end point, a composite of death, nonfatal myocardial infarction, unstable angina and late (>3 months after the exercise test) myocardial revascularization, occurred in 41 patients. Failure to achieve 85% of the age-predicted maximum heart rate was predictive of events (relative risk [RR] 2.47, 95% confidence interval [CI] 1.28 to 4.79, p=0.007); similarly, a low chronotropic index was predictive (RR 2.44, 95% CI 1.31 to 4.55, p=0.005). Even after adjusting for myocardial ischemia and other possible confounders, failure to achieve 85% of age-predicted maximum heart rate was predictive (adjusted RR 2.20, 95% CI 1.11 to 4.37, p=0.02). A low chronotropic index also remained predictive (adjusted RR 1.85, 95% CI 0.98 to 3.47, p=0.06). CONCLUSIONS Chronotropic incompetence is predictive of an adverse cardiovascular prognosis even after adjusting for echocardiographic myocardial ischemia.

Automated echocardiographic quantification of left ventricular volumes and ejection fraction: Validation in the intensive care setting

To validate automated boundary detection measurements of left ventricular volumes, cardiac output, and ejection fraction, we studied 50 patients in the intensive care unit. End-diastolic volume, end-systolic volume, and ejection fraction were calculated by automated boundary detection and compared with two-dimensional echocardiographic images. Automated boundary detection-derived cardiac output was compared with thermodilution measurements and Doppler calculations of flow through the aortic and pulmonic valves. Automated boundary detection agreed well with two-dimensional measurements for end-diastolic volume (r = 0.98), end-systolic volume (r = 0.98), and ejection fraction (r = 0.91). Cardiac output derived from automated boundary detection correlated with two-dimensional echocardiographic measurements (r = 0.84), thermodilution (r = 0.83), aortic valve Doppler (r = 0.75), and pulmonic valve Doppler (r = 0.60). Automated boundary detection measurements of left ventricular volumes, ejection fraction, and derived cardiac output are feasible in patients in intensive care units. This method yields rapid, accurate result compared with thermodilution, two-dimensional images, and Doppler measurements.

Systolic anterior motion of mitral valve after the posterior leaflet sliding advancement procedure

The posterior leaflet sliding advancement procedure was developed to prevent the occurrence of systolic anterior motion of mitral valve and consequently outflow obstruction after mitral annuloplasty. We present a patient with extremely redundant posterior mitral leaflet in whom outflow obstruction developed despite employment of this procedure. This case underscores the utility of preoperative and intraoperative echocardiography in surgical decision making. Systolic anterior motion can develop in some patients despite this new surgical technique.

Left ventricular diastolic dysfunction in lymphocytic myocarditis as assessed by Doppler echocardiography

Pulsed-wave Doppler echocardiography of left ventricular (LV) inflows was performed in 30 consecutive patients with biopsy-proven lymphocytic myocarditis. There were 21 men and 9 women (mean age 50 +/- 15 years). LV ejection fraction was < or = 30% in 73% of the patients. Sixty-six percent were in New York Heart Association functional class III to IV. Peak early (E) velocity, late (A) velocity, deceleration time and filling pattern were assessed. These values were compared with a control population. E velocity in lymphocytic myocarditis was significantly higher than in control subjects (79 +/- 34 vs 67 +/- 14 cm/s, p = 0.0034). A velocity was lower in patients with myocarditis than in control subjects (38 +/- 20 vs 49 +/- 12 cm/s, p = 0.0001). Correspondingly, the E/A ratio was greater in the myocarditis group (2.5 +/- 1.3 vs 1.5 +/- 0.5, p < 0.0001). In particular, mean deceleration time in patients with myocarditis was significantly lower than that of control subjects (151 +/- 52 vs 194 +/- 30 ms, p < 0.0001). Diastolic filling patterns were abnormal in 29 of 30 patients (97%) with lymphocytic myocarditis, revealing a restrictive pattern in 25, abnormal relaxation in 4 and a normal pattern in 1. Lymphocytic myo-carditis is therefore associated with LV diastolic dysfunction of a predominantly restrictive pattern.

Transthoracic Echocardiography Documents Prompt Resolution of Right Atrial Thrombus After Thrombolytic Therapy

Right atrial thrombi represent pulmonary emboli in transit, and they may be fatal in patients treated conservatively with anticoagulation. This case provides an opportunity to review echocardiographic findings and management decisions in this disease entity. As the literature now favors thrombolytic therapy in suitable patients, we present a case in which transthoracic echocardiography provided rapid assessment of the outcome of this form of therapy.

Circumflex Artery Aneurysm

The patient was a 71-year-old man who had a known circumflex artery aneurysm and coronary artery bypass surgery in 1982. The aneurysm was left intact because of difficulty in surgical removal at that time. Recently, because of symptoms …