Adult respiratory distress syndrome following thrombolytic therapy with APSAC for acute myocardial infarction.
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Anistreplase↗
Biomedical subjects
K Chatterjee
Publications and source records attributed to K Chatterjee.
Application of cine nuclear magnetic resonance imaging for sequential evaluation of response to angiotensin-converting enzyme inhibitor therapy in dilated cardiomyopathy.
Cine nuclear magnetic resonance (NMR) imaging was used to serially measure cardiovascular function in 17 patients with New York Heart Association class II or III heart failure and left ventricular ejection fraction less than or equal to 45% who were treated for 3 months with benazepril hydrochloride, a new angiotensin-converting enzyme inhibitor, while continuing treatment with diuretic agents and digoxin. Interobserver reproducibilities for ejection fraction (r = 0.94, SEE 3.3%), end-systolic volume (r = 0.98, SEE 10.6 ml), end-diastolic volume (r = 0.99, SEE 8.29 ml), end-systolic mass (r = 0.96, SEE 15.4 g), end-systolic wall stress (r = 0.91, SEE 10 dynes.s.cm-5) and end-systolic stress/volume ratio (r = 0.85, SEE 0.13) demonstrated applicability of cine NMR imaging for the serial assessment of cardiovascular function in response to pharmacologic interventions in patients with heart failure. During 12 weeks of treatment with benazepril, ejection fraction increased progressively from 29.7 +/- 2.2% (mean +/- SEM) to 36 +/- 2.2% (p less than 0.05), end-diastolic volume decreased from 166 +/- 14 to 158 +/- 12 ml (p = NS), end-systolic volume decreased from 118 +/- 12 to 106 +/- 11 ml (p less than 0.05), left ventricular mass decreased from 235 +/- 13 to 220 +/- 12 g (p less than 0.05), end-systolic wall stress decreased 29% from 90 +/- 5 to 64 +/- 5 dynes.s.cm-5 (p less than 0.05), end-systolic pressure decreased from 92.6 +/- 3.7 to 78.8 +/- 5.3 (p less than 0.05) and end-systolic stress/volume ratio, a load-independent index of contractility, decreased from 0.83 +/- 0.05 to 0.67 +/- 0.06 (p less than 0.05), demonstrating that improved ejection fraction is due to afterload reduction.
Analysis of Variance↗
Flosequinan, a new vasodilator: systemic and coronary hemodynamics and neuroendocrine effects in congestive heart failure.
OBJECTIVES: The aim of this study was to evaluate the immediate and long-term systemic and coronary hemodynamic, metabolic and neurohormonal effects of flosequinan in patients with congestive heart failure. BACKGROUND: Preliminary studies have shown that this new long-acting oral systemic vasodilator may have beneficial effects in patients with heart failure. METHODS: Thirteen patients with congestive heart failure were studied. Systemic and coronary hemodynamic, metabolic and neurohormonal effects of flosequinan were assessed acutely with repeat systemic hemodynamic studies after 6 weeks of treatment. RESULTS: The administration of flosequinan acutely and after long-term treatment, resulted in a significant increase in cardiac index, stroke work index and stroke volume index with a reduction in systemic and pulmonary vascular resistances. The improvement in ventricular function was associated with an improvement in left ventricular efficiency without a change in myocardial oxygen consumption or coronary sinus blood flow. Myocardial oxygen extraction and net myocardial lactate extraction also did not change significantly with flosequinan therapy. Systemic catecholamine levels and myocardial catecholamine balance did not change. Plasma arterial and coronary sinus atrial natriuretic factor concentrations were elevated at baseline; the latter concentrations at the level of the great cardiac vein were significantly higher than those of arterial concentrations, indicating increased left ventricular release of atrial natriuretic factor in congestive heart failure. Both arterial and coronary sinus atrial natriuretic factor levels were significantly reduced with the administration of flosequinan at peak effect in association with an improvement in systemic hemodynamics. CONCLUSIONS: Flosequinan therapy in patients with congestive heart failure results in a sustained beneficial hemodynamic action and improved cardiac performance without an increase in metabolic demand or activation of the sympathetic nervous system.
Aged↗
Pathogenesis of low output in right ventricular myocardial infarction.
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Animals↗
Dipyridamole perfusion scintigraphy: the experience with its application in one hundred seventy patients with known or suspected unstable angina.
We evaluated the safety, accuracy, and potential clinical utility of intravenous dipyridamole perfusion scintigraphy with thallium-201 in 170 patients, 78 with suspected and 92 with known unstable angina. All had coronary angiography. Noncardiac side effects (26%), induced chest discomfort (44%), and ST segment changes (12%) were similar in the two groups. No significant arrhythmias occurred. Two patients had prolonged chest pain, both with extensive reversible image abnormalities and associated creatinine kinase-MB release. Both had elective bypass surgery. Twenty-eight patients had normal coronary arteries, and 35 had single-vessel disease. Scintigraphic per patient sensitivity and specificity were 91% and 79% with a per vessel sensitivity of 74% and a per vessel specificity of 78% without between-group differences. During a brief follow-up period, 62 patients with image abnormalities had coronary revascularization, and there were seven deaths without intergroup differences. In a similar patient group that did not have angiography, scintigraphic defects were less frequent and less extensive, revascularization was not performed, and subsequent deaths occurred less often. Dipyridamole perfusion scintigraphy is an accurate alternative to exercise testing in the evaluation of patients with unstable angina pectoris. Although not without risk, the method appears relatively safe and should be considered as a guide to diagnosis, and probably to prognosis and management.
Adult↗
Decreased coronary sinus oxygen content: a predictor of adverse prognosis in patients with severe congestive heart failure.
Patients with congestive heart failure have abnormal coronary hemodynamics, characterized by decreased coronary sinus oxygen content, increased coronary sinus blood flow and increased myocardial oxygen consumption. To evaluate their prognostic importance, the clinical characteristics and systemic and coronary hemodynamics were related to survival in 91 patients with severe congestive heart failure and decreased ejection fraction (25.5 +/- 10% [mean +/- SD]). In 69 patients congestive heart failure was due to or secondary to coronary artery disease (group 1) and in 22 it was due to idiopathic dilated cardiomyopathy (group 2). Five patients were in functional class II, 48 in class III and 38 in class IV. The median survival time was 20.7 months. As assessed with the Cox proportional hazards model, coronary sinus oxygen content was most strongly associated with a poor prognosis. On the basis of a comparison between the lowest (coronary sinus oxygen content less than or equal to 4.44 vol%) and highest quintile (coronary sinus oxygen content greater than 4.44 vol%), a low coronary sinus oxygen content was associated with a 2.34-fold increased risk of dying (95% confidence interval, 1.31 to 4.08). A low systolic blood pressure and a high diastolic pulmonary artery pressure were also significantly associated with increased mortality. Patients in the subgroup with a low coronary sinus oxygen content had values for functional class, ejection fraction and systemic hemodynamics similar to those of patients in the subgroup with high coronary sinus oxygen content. It is concluded that a low coronary sinus oxygen content indicative of noncompensated metabolic demand suggests a poor prognosis in patients with severe congestive heart failure.
Aged↗
Normal and diffusely abnormal myocardium in humans: functional and metabolic characterization with P-31 MR spectroscopy and cine MR imaging.
The current study tested the concept that cine magnetic resonance (MR) imaging and phosphorus-31 MR spectroscopy might be used to provide a comprehensive evaluation of the functional and metabolic status of the myocardium in humans. Thirteen patients with congestive cardiomyopathy and eight healthy volunteers were imaged at 1.5 T with the one-dimensional chemical shift imaging technique for localization of P-31 MR spectroscopy and an electrocardiographically referenced gradient refocused sequence for imaging of the heart. Prominent peaks in the PDE and PME regions were observed in cardiomyopathic patients, but only the former peak was measured. The PCr/beta-ATP peak ratio was not significantly lower in cardiomyopathic patients compared with healthy subjects (1.51 +/- 0.08 vs 1.54 +/- 0.04). The ratios of PDE/PCr (0.80 +/- 0.07 vs 0.54 +/- 0.10) (P less than or equal to .01) and PDE/beta-ATP (1.19 +/- 0.10 vs 0.84 +/- 0.08) (P less than or equal to .05) were significantly higher in patients with dilated cardiomyopathy compared with healthy volunteers. Left ventricular systolic wall thickening was significantly lower and left ventricular peak and end-systolic wall stress and mass were significantly higher in cardiomyopathic patients compared with healthy volunteers. Thus, localized, gated P-31 MR spectroscopy combined with cine MR imaging allowed identification of both abnormal myocardial phosphate metabolism and abnormal ventricular function. While this study suggests that increased myocardial PDEs may be a marker for abnormal myocardium, the sensitivity and specificity of this marker need to be further evaluated.
Adenosine Triphosphate↗
Polymorphous ventricular tachycardia associated with acute myocardial infarction.
BACKGROUND: During a 2.9-year period, 11 patients developed polymorphous ventricular tachycardia 1-13 days after acute anterior (seven patients) or inferior (four patients) myocardial infarction. None of the 11 patients had sinus bradycardia (mean heart rate, 90 +/- 23 beats/min), but three had a sinus pause immediately before the onset of polymorphous ventricular tachycardia. In all 11 patients, the QT interval and corrected QT interval (QTc) were normal or minimally prolonged (QT, 385 +/- 34 msec; QTc, 442 +/- 40 msec). None had significant hypokalemia (mean serum potassium concentration, 4.3 +/- 0.5 meq/l) or a grossly abnormal serum magnesium or calcium concentration (2.1 +/- 0.4 and 8.9 +/- 0.7 mg/dl, respectively). METHODS AND RESULTS: Immediately before the onset of polymorphous ventricular tachycardia, symptoms and/or electrocardiographic changes consistent with recurrent myocardial ischemia occurred in nine of 11 patients. One patient died before drug therapy could be initiated. Lidocaine was used in 10 patients and proved to be effective in only one. Intravenous procainamide was used in six patients: one improved, and five had recurrence of polymorphous ventricular tachycardia. Bretylium was used in five patients and was ineffective in all cases. Overdrive pacing was used in four patients and failed to suppress recurrent arrhythmias in all cases. Four patients with persistent polymorphous ventricular tachycardia unresponsive to lidocaine, procainamide, or bretylium responded to intravenous amiodarone. One patient with polymorphous ventricular tachycardia that was consistently preceded by ST segment elevation responded to intravenous nitroglycerin. Two patients with persistent polymorphous ventricular tachycardia and obvious recurrent ischemia unresponsive to pharmacological intervention responded to emergency coronary revascularization. A third patient who experienced recurrent angina and polymorphous tachycardia was initially stabilized with pharmacological therapy but subsequently underwent elective revascularization and has remained stable without antiarrhythmic therapy. CONCLUSIONS: Post-myocardial infarction polymorphous ventricular tachycardia is not consistently related to an abnormally long QT interval, sinus bradycardia, preceding sinus pauses, or electrolyte abnormalities. This arrhythmia has a variable response to class I antiarrhythmics but may be suppressed by intravenous amiodarone therapy. It is often associated with signs or symptoms of recurrent myocardial ischemia. Furthermore, coronary revascularization appears to be effective in preventing the recurrence of polymorphous ventricular tachycardia when associated with recurrent postinfarction angina.
Aged↗
Transvenous coronary ultrasound imaging. A novel approach to visualization of the coronary arteries.
BACKGROUND: Catheter-based ultrasound is a new imaging modality to examine endovascular detail in the coronary circulation. This technique requires direct placement of the catheter in the arterial segment of interest. METHODS AND RESULTS: We examined the feasibility of a less invasive approach by imaging the coronary arterial circulation by using a 5F (30 MHz) imaging catheter placed in the cardiac venous system. Using simultaneous fluoroscopy, we studied anesthetized closed-chest dogs (n = 6) and human subjects undergoing right heart catheterization (n = 11). After cannulation of the coronary sinus, the circumflex coronary artery (Cx) was visualized from the great cardiac vein (GCV), and on advancing the catheter into the anterior interventricular vein (AIV), the left anterior descending artery (LAD) was identified. Where artery and vein were parallel to each other, circular cross-sectional images of the coronary artery were obtained, whereas oblique and transverse orientation of artery to vein produced ellipsoid images or long-axis images. In the dogs, ultrasound-determined cross-sectional area of the coronary arteries (4.81 +/- 0.18 mm2) correlated closely with angiography (4.77 +/- 0.21 mm2) (r = 0.91, p less than 0.001). In humans, the Cx was readily visualized from the GCV in all subjects but because of anatomic variability, the LAD was seen less consistently from the AIV (73%). There was significant correlation between ultrasound-determined cross-sectional areas of the coronary arteries (8.25 +/- 0.34 mm2) with those from angiography (8.59 +/- 0.3 mm2) (r = 0.82, p = 0.001) in humans. In all subjects, the ultrasound transducer could be safely advanced into the AIV to the cardiac apex. Limitations of the technique include ultrasonic penetration problems, caused in part by the large size of human coronary veins and variability in artery-vein relations. CONCLUSIONS: We conclude that transvenous imaging of coronary arteries with intravascular ultrasound is a less invasive, promising new approach to the study of structure and morphology in the coronary vasculature.
Animals↗
Congestive heart failure. New frontiers.
Congestive heart failure is a common syndrome with high mortality in its advanced stages. Current therapy includes the use of vasodilator drugs, which have been shown to prolong life. Despite current therapy, mortality remains high in patients with severe heart failure. Potent new inotropic vasodilators have improved ventricular performance but have not prolonged life in patients with end-stage heart failure. Serious arrhythmias are implicated in the sudden deaths of 30% to 40% of patients with severe heart failure, but the benefits of antiarrhythmic therapy have not been established. Upcoming trials will address this question. Ventricular remodeling and progressive dilatation after myocardial infarction commonly lead to congestive heart failure; early unloading of the ventricle with an angiotensin-converting enzyme inhibitor may attenuate these events. These findings support the concept that angiotensin-converting enzyme inhibitors may be useful in managing heart failure of all degrees of severity, including left ventricular dysfunction and end-stage heart failure. Part of the damage that may occur with acute myocardial infarction, particularly in this era of thrombolysis therapy, is reperfusion injury, which may be mediated by oxygen-derived free radicals. Better knowledge of the mechanisms and treatment of myocardial infarction, the leading cause of congestive heart failure, may help prevent or attenuate the development of this syndrome.
Anti-Arrhythmia Agents↗
Predicting 1-year outcome following acute myocardial infarction: physicians versus computers.
Whether decision rules derived statistically from patient data can produce better decisions than an expert clinician or a model of the expert clinician (expert system) is controversial. We examined this issue in the context of predicting cardiac death by 1 year for patients discharged from the hospital following acute myocardial infarction. Decision rules were derived from a base sample of 781 patients. These decision rules and three experienced cardiologists then estimated probability of death by 1 year for each patient in a separate test sample (n = 400). In our evaluation of the performance of the decision rules and physicians, we detected no differences, although the decision rules and physicians tended to classify the patients somewhat differently. Further multivariate analyses on the physicians' predictions showed that two of the physicians paid attention to somewhat different variables than the third physician. Lack of agreement among expert cardiologists would complicate modeling of a consensual decision-making process within the framework of an expert system.
Aged↗
Interstudy reproducibility of dimensional and functional measurements between cine magnetic resonance studies in the morphologically abnormal left ventricle.
The validity of geometric formulas to derive mass and volumes in the morphologically abnormal left ventricle is problematic. Imaging techniques that are tomographic and therefore inherently three-dimensional should be more reliable and reproducible between studies in such ventricles. Determination of reproducibility between studies is essential to define the limits of an imaging technique for evaluating the response to therapy. Sequential cine magnetic resonance (MR) studies were performed on patients with dilated cardiomyopathy (n = 11) and left ventricular hypertrophy (n = 8) within a short interval in order to assess interstudy reproducibility. Left ventricular mass, volumes, ejection fraction, and end-systolic wall stress were determined by two independent observers. Between studies, left ventricular mass was highly reproducible for hypertrophied and dilated ventricles, with percent variability less than 6%. Ejection fraction and end-diastolic volume showed close reproducibility between studies, with percent variability less than 5% End-systolic volume varied by 4.3% and 4.5% in dilated cardiomyopathy and 8.4% and 7.2% in left ventricular hypertrophy for the two observers. End-systolic wall stress, which is derived from multiple measurements, varied the greatest, with percent variability of 17.2% and 15.7% in dilated cardiomyopathy and 14.8% and 13% in left ventricular hypertrophy, respectively. The results of this study demonstrate that mass, volume, and functional measurements are reproducible in morphologically abnormal ventricles.
Adult↗
Comparison of transesophageal echocardiographic and scintigraphic estimates of left ventricular end-diastolic volume index and ejection fraction in patients following coronary artery bypass grafting.
Transesophageal echocardiography (TEE) has become a commonly used monitor of left ventricular (LV) function and filling during cardiac surgery. Its use is based on the assumption that changes in LV short-axis ID reflect changes in LV volume. To study the ability of TEE to estimate LV volume and ejection immediately following CABG, 10 patients were studied using blood pool scintigraphy, TEE, and thermodilution cardiac output (CO). A single TEE short-axis cross-sectional image of the LV at the midpapillary muscle level was used for area analysis. Between 1 and 5 h postoperatively, simultaneous data sets (scintigraphy, TEE, and CO) were obtained three to five times in each patient. End-diastolic (EDa) and end-systolic (ESa) areas were measured by light pen. Ejection fraction area (EFa) was calculated (EFa = (EDa - ESa)/EDa). When EFa was compared with EF by scintigraphy, correlation was good (r = 0.82 SEE = 0.07). EDa was taken as an indicator of LV volume and compared with LVEDVI which was derived from EF by scintigraphy and CO. Correlation between EDa and LVEDVI was fair (r = 0.74 SEE = 3.75). The authors conclude that immediately following CABG, a single cross-sectional TEE image provides a reasonable estimate of EF but not LVEDVI.
Adult↗
Systemic and coronary haemodynamics and pharmacodynamics of enalapril and enalaprilat in congestive heart failure.
Enalapril is an effective angiotensin-converting enzyme (ACE) inhibitor which produces salutary, beneficial haemodynamic effects in patients with congestive heart failure. Enalapril also produces beneficial neurohumoral changes, as well as improving abnormal coronary haemodynamics and myocardial energetics that are frequently encountered in these patients. Administration of enalapril once or twice daily appears to be quite effective during maintenance therapy in patients with chronic congestive heart failure.
Aldosterone↗
Should the asymptomatic patient with a significant proximal LAD stenosis undergo PTCA?
The approach to a proximal LAD stenosis in an asymptomatic patient depends on a number of factors. Most important among these are the presence and extent of ischemia, anatomic considerations, and the functional status of the myocardium subserved by the vessel. In patients with functionally and hemodynamically insignificant disease with no ischemia, it is appropriate simply to follow the patient and to modify the risk factors for atherosclerosis if they exist. All three of the currently available modalities are appropriate in individual patients, including medical management, percutaneous balloon angioplasty, and surgical revascularization. In ambiguous cases, the available studies suggest no benefit from aggressive strategies; therefore, a conservative approach that minimizes side effects and complications of treatment is best.
Angioplasty, Balloon, Coronary↗
Managing congestive heart failure medically--what have we learned?
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Diastole↗
Newer oral inotropic agents: phosphodiesterase inhibitors.
Phosphodiesterase inhibitors are potent inotropic and vasodilator agents that have attracted intense investigative interest in recent years as a potential treatment for congestive heart failure resulting from left ventricular dysfunction. These agents increase intracellular Ca availability by increasing cyclic AMP levels and improve cardiac performance by (a) enhancing contractility, (b) reducing left ventricular afterload, and (c) improving diastolic compliance of the left ventricle. Increased cardiac work leads to an increase in myocardial oxygen consumption, but increased coronary flow prevents an imbalance of myocardial oxygen supply and demand. Available data indicate that renal perfusion may increase as a result of the increase in cardiac output, but much of the decrease in systemic vascular resistance apparently occurs in musculoskeletal tissue. The hemodynamic improvements associated with these agents are well documented, but whether they actually affect the prognosis remains uncertain.
Coronary Vessels↗
Long-term predictors of sudden and low output death in chronic congestive heart failure secondary to coronary artery disease.
Clinical, hemodynamic and neurohumoral variables in 238 patients with chronic congestive heart failure (CHF) secondary to coronary artery disease were analyzed to determine potential predictors of mortality in a large population and to allow analysis according to mode of death (sudden or low output death). All variables were assessed before initiation of treatment with vasodilators (converting enzyme inhibitors, direct acting vasodilators) or with the nonglycoside, noncatecholamine class of inotropic agents. Survival outcome was determined as alive, sudden death or low output death. When all variables except ejection fraction were analyzed by Cox multiple regression analysis, the most important independent predictor of all deaths was the baseline plasma renin activity (p less than 0.001). When subdivided by cause of cardiovascular death, baseline plasma renin activity was retained as the most important determinant of low output death (p less than 0.001), whereas baseline left ventricular stroke work index (p less than 0.001), pulmonary capillary wedge pressure (p less than 0.002) and absence of sinus rhythm (p less than 0.006) were the most powerful independent predictors of sudden death. Plasma norepinephrine was markedly elevated in the group dying of low output, but only modestly elevated in the group of survivors and the group dying suddenly. However, baseline norepinephrine was not found to be an important independent predictor of mortality in any of the subgroups. Plasma renin activity, but not plasma norepinephrine, is a powerful independent prognostic determinant of mortality in this group of patients with CHF.
Adult↗