Jan Laws Houghton

Relation among impaired coronary flow reserve, left ventricular hypertrophy and thallium perfusion defects in hypertensive patients without obstructive coronary artery disease

Abstract Invasive Doppler catheter-derived coronary flow reserve, echocardiographic measurements of left ventricular hypertrophy and intravenous dipyridamole-limited stress thallum-201 scintigraphy were compared in 48 patients (40 were hypertensive or diabetic) with clinical ischemic heart disease and no or coronary artery disease. Abnormal vasodilator reserve (ratio The decrement in flow reserve was not linearly related to the of left ventricular hypertrophy. Abnormal vasodilator reserve subsets found in hypertensive patients were defined on the basis of basal flow velocity, indexed left ventricular mass and clinical factors. In this series, diabetes did not cause a detetable additional decrement in flow reserve above that found with hypertension alone. These findings demonstrate that thallium perfusion defects are associated with depressed coronary vasodilator reserve in hypertensive patients without obstructive coronary artery disease, Left ventricular hypertrophy by indexed mass criteria is predictive of which hypertensive patients are likely to have thallium defects. Depressed coronary reserve is typically found in hypestensive patients with hypertrophy and increased basal coronary flow velocity, but less typical presentations including hypertrophy and normal or low coronary low velocity are found in advanced hypertensive disease.

Morphologic, hemodynamic and coronary perfusion characteristics in severe left ventricular hypertrophy secondary to systemic hypertension and evidence for nonatherosclerotic myocardial ischemia☆

Patients with the clinical diagnosis of ischemic heart disease who were found to be free of significant coronary artery atherosclerotic disease (n = 150) underwent coronary vasodilator reserve testing, 2-dimensional echocardiography, and dipyridamole limited-stress thallium testing. After exclusions (predominantly for technically poor coronary artery Doppler signals or suboptimal echocardiography), 100 patients formed the study population. The purpose was to characterize typical cardiac and coronary artery findings in hypertensive patients with severe left ventricular (LV) hypertrophy (n = 15) and to investigate the evidence for myocardial ischemia unrelated to coronary atherosclerosis in early and advanced hypertensive heart disease. Normotensive and hypertensive control groups without LV hypertrophy (n = 12 and 34, respectively) were used for comparison. Severe LV hypertrophy was defined as LV mass index greater than or equal to 50% above established gender specific norms using 2-dimensional-directed M-mode echocardiography and the cube equation corrected to agree with necropsy estimates of mass. Clinical characteristics more often associated with severe LV hypertrophy were black race (67%), diabetes mellitus (33%), proteinuria (47%) and elevated creatinine (1.5 +/- 0.9 mg/dl). Baseline electrocardiograms and dipyridamole limited-stress thallium scans were highly likely to be abnormal (94 and 73%, respectively). Both eccentric and concentric cardiac hypertrophies were found in the severe group. Ejection fraction was significantly lower (0.51 vs 0.68, p = 0.002) and basal coronary flow velocity higher (12.0 vs 5.0 cm/s, p = 0.0004) among these patients when compared with normotensive control patients. Coronary flow reserve did not differ between control groups but was significantly depressed in patients with severe LV hypertrophy (2.5 vs 3.9, p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship of left ventricular mass to impairment of coronary vasodilator reserve in hypertensive heart disease

An impaired coronary vasodilator reserve has been demonstrated in all stages of hypertensive heart disease but is most likely in the setting of hypertrophy. The decrease in coronary flow reserve has, however, not been predictable previously. We postulated that flow reserve depression might be related to a left ventricular mass threshold. Seventy-two patients (82% with hypertension) with suspected ischemic heart disease who were found to be free of significant coronary artery disease at cardiac catheterization were evaluated utilizing the intracoronary Doppler catheter and two-dimensional directed M-mode echocardiography for determination of coronary flow reserve and left ventricular mass. For left ventricular mass indexed (LVMI) by body surface area (BSA) greater than or equal to 50% above normal using established gender-specific norms, American Society of Echocardiography (ASE) and PENN methods (correction of LV mass by regression equation agreeing with necropsy estimates of mass) predicted impairment of flow reserve (p = 0.005 and 0.009, respectively). Unindexed left ventricular mass and LVMI by height were not helpful in this regard. Using the ASE method for LV mass determination, coronary flow reserve was moderately depressed (2.4 +/- 1.0) for those with LVMI greater than or equal to 50% above normal; in comparison, flow reserve was normal (3.5 +/- 1.3) for those with LVMI less than 50% above normal. A rare patient was able to maintain a normal flow reserve when ASE- and Penn-indexed mass estimates were greater than or equal to 50% above normal, but only in the setting of a markedly elevated mean arterial pressure.

Possible Triggering of Paroxysmal Atrial Fibrillation in Normal Hearts by Psychological Stressors: A Report of Two Cases

Paroxysmal atrial fibrillation was triggered by psychological stress in two patients, both of whom had normal echocardiograms and coronary angiography. Neither patient was alcoholic or had ingested ethanol in relation to the onset of atrial fibrillation and both were free of metabolic derangements. Possible mechanisms involved in the triggering of atrial fibrillation are discussed.

Case Report: Acute Presentation of Pseudo Myocardial Infarction Secondary to Metastatic Cancer

Electrocardiographic ST segment changes that mimic myocardial infarction (MI) may occur secondary to metastatic carcinoma. Presented here is a case in which symptomatology suggestive of acute MI occurred with impressive new anterior ST segment elevation in a patient with a history of laryngeal carcinoma. Clinical options in this setting are discussed, including use of thrombolytic agents and acute catheterization.

Postpartum myocardial infarction treated by balloon coronary angioplasty

Acute myocardial infarction in pregnancy is a rare event that carries substantial morbidity and mortality. New technologies have been developed in cardiology to open obstructed vessels during the acute evolution of coronary thrombosis. We present a case of acute postpartum myocardial infarction in a woman with class F/R diabetes. She underwent successful balloon angioplasty but developed chest pain suspicious of angina pectoris 6 weeks after the procedure. A thallium scan demonstrated fixed defects in the inferoposterior and posterolateral segments and minimal apical redistribution. This represents the second case of angioplasty performed in pregnancy and the first for an acute myocardial infarction.