Journal of the American College of Cardiology
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J. Am. Coll. Cardiol. · Aug 1989
Evaluation of ventricular contractility indexes in the dog with left ventricular dysfunction induced by rapid atrial pacing.
Eight dogs were studied by simultaneous invasive hemodynamic and two-dimensional echocardiographic methods to determine whether left ventricular contractility is altered by 2 weeks of rapid atrial pacing. Additionally, this study evaluated the response of three ventricular contractility indexes to both the pacing intervention and acute load alteration. The indexes compared were ejection fraction, peak systolic pressure to end-systolic volume index ratio (SBP/ESVI) and end-systolic wall stress to end-systolic volume index ratio (ESWS/ESVI). ⋯ There were high correlations for the changes in SBP/ESVI and ejection fraction (r = 0.94, p less than 0.001) and ESWS/ESVI and ejection fraction (r = 0.89, p less than 0.003). Acute afterload alteration with phenylephrine depressed ejection fraction but not SBP/ESVI or ESWS/ESVI. Therefore, this study demonstrates 1) that left ventricular contractility is markedly depressed in the dog by 2 weeks of rapid atrial pacing, and 2) that SBP/ESVI and ESWS/ESVI are superior to ejection fraction as ventricular contractility indexes because these ratios accurately measure contractility changes but are influenced less by after-load conditions.
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J. Am. Coll. Cardiol. · Aug 1989
Marfan's syndrome: natural history and long-term follow-up of cardiovascular involvement.
A retrospective analysis was undertaken to define the natural history and long-term follow-up of a group of patients with Marfan's syndrome. Eighty-four patients were diagnosed between January 1959 and June 1987 as having Marfan's syndrome; 68% were male; their ages ranged from 2 to 67 years (mean 26.6). Sixteen patients constituted the early surgical group (those who underwent surgery before 1979; mean age 36.1 years). ⋯ Sixty-one percent of deaths were the result of aortic dissection or rupture or sudden cardiac death. Of the 50 survivors, 98%, including all patients in the late surgical group, were in functional class I or II. Overall survival at 5, 10 and 15 years after operation was 78.4%, 57.1% and 49.5%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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J. Am. Coll. Cardiol. · Jul 1989
Nonischemic sustained ventricular tachycardia: clinical outcome in 12 patients with arrhythmogenic right ventricular dysplasia.
The clinical course and long-term follow-up of 12 patients with arrhythmogenic right ventricular dysplasia causing ventricular tachycardia are presented. No patient had a history of congestive heart failure and the cardiothoracic ratio measured less than or equal to 0.5 in all patients. All 12 patients were symptomatic during ventricular tachycardia; syncope occurred in 4. ⋯ Recurrence of symptomatic and documented sustained monomorphic ventricular tachycardia occurred in eight patients and could not be predicted by results of long-term ECG monitoring, treadmill exercise testing or programmed stimulation. In conclusion, despite recurrence of ventricular tachycardia, patients with arrhythmogenic right ventricular dysplasia have a favorable outcome when treated medically. Noninvasive studies (imaging techniques, ambulatory ECG monitoring and exercise testing) provide data that may be sufficient in diagnosing arrhythmogenic right ventricular dysplasia.
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J. Am. Coll. Cardiol. · May 1989
Comparative StudyInstantaneous and continuous cardiac output obtained with a Doppler pulmonary artery catheter.
A newly developed, flow-directed, Doppler pulmonary artery catheter, capable of measuring instantaneous and continuous cardiac output, was evaluated in both an in vitro pump model and an animal model. Quantitative flow was calculated with use of the instantaneous, space-average velocity (obtained from the velocity profile) and the instantaneous area (obtained from the vessel diameter) and compared with electromagnetic flow. Additionally, simultaneous thermodilution flow measurements were obtained. ⋯ However, Doppler determinations of flow remained more accurate than did simultaneous thermodilution measurements (r2 = 0.73, m = 0.79, SEE = 0.72). Accurate, continuous and instantaneous cardiac output measurements appear possible with use of a flow-directed, Doppler pulmonary artery catheter. This catheter system also provides instantaneous diameter measurements and mapping of instantaneous velocity profiles within the main pulmonary artery and may lead to more accurate Doppler-derived assessment of cardiac output in humans.