James M. Hopkins

Assessment of right ventricular function using two-dimensional echocardiography☆

With the use of two-dimensional echocardiography (2DE), we analyzed apical and subcostal four-chamber views for evaluation of right ventricular (RV) function in 30 individuals as compared to RV ejection fraction (RVEF) obtained by radionuclide angiography. In addition to previously reported parameters of changes in areas and chords, a new simple measurement of tricuspid annular excursion was correlated with RVEF. A close correlation was noted between tricuspid annular plane systolic excursion (TAPSE) and RVEF (r = 0.92). The RV end-diastolic area (RVEDA) and percentage of systolic change in area in the apical four-chamber view also showed close correlation with RVEF (r = -0.76 and 0.81); however, the entire RV endocardium could only be traced in about half of our patients. The end-diastolic transverse chord length and the percentage of systolic change in chord length in the apical view showed a poor correlation with RVEF. The correlation between RVEF and both areas and chords measured in the subcostal view was poor. It is concluded that the measurement of TAPSE offers a simple echocardiographic parameter which reflects RVEF. This measurement is not dependent on either geometric assumptions or traceable endocardial edges. When the endocardial outlines could be traced, the apical four-chamber view was superior to the subcostal view in assessment of RV function.

Hemodynamic effects of intravenous flecainide relative to the level of ventricular function in patients with coronary artery disease

Flecainide, a new antiarrhythmic agent with poorly defined hemodynamic actions, was studied in 22 patients with coronary artery disease. Intravenous infusions of 1 mg/kg and 2 mg/kg resulted in respective increases in right atrial pressure (12%, p less than 0.05; 15%, p less than 0.01), mean pulmonary artery pressure (27%, p less than 0.01; 28%, p less than 0.01), and pulmonary capillary wedge pressure (44%, p less than 0.05; 33%, p less than 0.01). Cardiac index decreased 8% (p less than 0.05) after 1 mg/kg flecainide and 12% (p less than 0.05) after the 2 mg/kg dose. The mean left ventricular ejection fraction decreased by 15% (p less than 0.01) and 16% (p less than 0.01), respectively, 10 minutes after 1 mg/kg and 2 mg/kg of flecainide. Minimal increases in the heart rate (less than 5%) and no significant change in arterial pressure occurred 5 to 10 minutes after flecainide and were associated with borderline and variable increases in pulmonary and systemic vascular resistances. Flecainide diluent did not induce changes in pulmonary capillary wedge pressure or left ventricular ejection fraction. Thus, flecainide exerts a moderate but significant negative inotropic effect which may be clinically significant in patients with severely compromised ventricular function.

Verapamil in chronic stable angina: Amelioration of pacing-induced abnormalities of left ventricular ejection fraction, regional wall motion, lactate metabolism and hemodynamics☆

Abstract The effects of intravenously administered verapamil (bolus dose of 0.145 mg/kg body weight, followed by continuous infusion at 0.005 mg/kg per min) on myocardial ischemia induced by incremental coronary sinus pacing were investigated in 12 patients with coronary artery disease undergoing diagnostic angiography. The effects were determined with respect to differences between changes under control pacing conditions and after verapamil in the transmyocardial gradients of lactate, systemic hemodynamics and in left ventricular ejection fraction and regional wall motion abnormalities measured with gated radionuclide ventriculography. Control and drug data could not be matched for four patients because of the development of atrioventricular (A-V) Wenckebach block at lower pacing rates during verapamil infusion. In the remaining eight patients, under control conditions, pacing to a mean maximal heart rate of 120.6 ± 10.8 beats/min produced moderate to severe chest pain in all; the left ventricular ejection fraction decreased from 0.59 ± 0.08 to 0.47 ± 0.07 (−20.2 percent, p The overall data, demonstrating that verapamil, when given under steady state conditions of drug administration, prevents or greatly attenuates the ischemic consequences of incremental coronary sinus pacing in patients with coronary artery disease, provide objective evidence for the clinical utility of the compound in exertional angina. Controlled clinical trials during oral therapy with the drug are therefore indicated.

Chronic effects of myocardial infarction on right ventricular function: A noninvasive assessment

To assess the chronic effects of myocardial infarction on right ventricular function, 48 subjects were studied utilizing radionuclide angiography and two-dimensional echocardiography. Ten were normal subjects (group I), 11 had previous inferior wall myocardial infarction (group II), 10 had previous anteroseptal infarction (group III), 11 had combined anteroseptal and inferior infarction (group IV) and 6 had extensive anterolateral infarction (group V). The mean (+/- standard deviation) left ventricular ejection fraction was 0.66 +/- 0.03 in group I, 0.58 +/- 0.02 in group II, 0.52 +/- 0.02 in group III, 0.33 +/- 0.03 in group IV and 0.33 +/- 0.01 in group V. No systematic correlation between left and right ventricular ejection fraction was observed among the groups. The mean right ventricular ejection fraction was significantly reduced in the presence of inferior myocardial infarction (0.30 +/- 0.03 in group II and 0.29 +/- 0.03 in group IV compared with 0.43 +/- 0.02 in group I [p less than 0.001]). The group II and IV patients also had increased (p less than 0.001) right ventricular end-diastolic area and decreased (p less than 0.001) right ventricular free wall motion by two-dimensional echocardiography. In the presence of anteroseptal infarction (group III), right ventricular free wall motion was increased (p less than 0.05) compared with normal subjects (group I). Thus, the effects of prior myocardial infarction on right ventricular function depend more on the location of infarction than on the extent of left ventricular dysfunction. Inferior infarction was commonly associated with reduced right ventricular ejection fraction and increased right ventricular end-diastolic area. The right ventricular free wall excursion was increased in the presence of anteroseptal infarction, suggested loss of contribution of interventricular septal contraction to right ventricular ejection.

Exercise-induced regional wall motion abnormalities on radionuclide angiography: Lack of reliability for detection of coronary artery disease in the presence of valvular heart disease

Exercise-induced regional wall motion abnormalities on radionuclide angiography have been thought to be a reliable indicator of coronary artery disease. To evaluate their reliability, particularly in patients with valvular heart disease, exercise radionuclide angiography was performed in 12 normal subjects, 35 patients with coronary artery disease and 19 patients with valvular heart disease and normal coronary arteries. Exercise-induced regional wall motion abnormalities were found in none of the normal subjects, 63 percent of the patients with coronary artery disease and 42 percent of those with valvular heart disease and were predominantly inferoapical in location in the group with valvular heart disease. We conclude that exercise-induced regional wall motion abnormalities are not reliable for the detection of coronary artery disease in patients with valvular heart disease.

Comparative effects of oral acebutolol and propranolol at rest and during exercise in ischemic heart disease: Double-blind placebo crossover study utilizing radionuclide ventriculography

Acebutolol is a new investigational beta-antagonist which has intrinsic sympathomimetic and cardioselective properties. In this study its effects on the ischemic consequences following supine bicycle exercise were compared to those of propranolol in 16 patients with chronic stable coronary artery disease (CAD) using a double-blind placebo crossover protocol and equilibrium radionuclide ventriculography. In eight patients (group I), the left ventricular ejection fraction (LVEF) at peak exercise fell under control conditions. During chronic acebutolol therapy (400 mg thrice daily), the exercise-induced LVEF (means +/- 1 SD) was significantly higher (37.1 +/- 15.5% versus 42.2 +/- 14.3%; p less than 0.05). The corresponding values during placebo and during propranolol (80 mg thrice daily) were 39.2 +/- 12.3% versus 43.4 +/- 14.8% (p = 0.07). In eight patients (group II) in whom supine bicycle exercise produced increases in LVEF, both acebutolol (58.8 +/- 5.4% versus 53.8 +/- 4.4%) and propranolol (57.8 +/- 5.7% versus 54.1 +/- 4.9%) attenuated the increases. In neither group was the resting LVEF reduced by acebutolol or propranolol. The data show that acebutolol and propranolol are approximately equipotent in minimizing the radionuclide left ventriculographic manifestations of myocardial ischemia induced by supine bicycle exercise.