American heart journal
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American heart journal · Jan 1981
HLA-DRW4 antigen linkage in patients with hypertrophic obstructive cardiomyopathy.
To determine the association of histocompatibility (HLA) genes in patients with hypertrophic cardiomyopathy, we determined HLA-A, HLA-B, HLA-C, and HLA-DR specificities in 33 Japanese patients (15 with the obstructive type off hypertrophic cardiomyopathy, and 18 with the nonobstructive type). HLA-DRW4 was found in 73% of patients with hypertrophic obstructive cardiomyopathy, as compared to 33% of 144 normal controls (p < 0.005). ⋯ Thus, hypertrophic obstructive cardiomyopathy is associated with genes in the HLA-DR region and immunogenetic factors linked to HLA appear to play a role in the pathogenesis. This work is the first attempt at demonstration of HLA-DR antigen in hypertrophic cardiomyopathy.
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American heart journal · Dec 1980
Shortcomings of the Lown grading system for observational or experimental studies in ischemic heart disease.
The Lown grading system uses three levels of frequency and four complex features to grade ventricular arrhythmias. The seven Lown grades are mutually exclusive (a patient can be in only one grade) and hierarchical (higher grades indicate increased likelihood of death). We evaluated the ability of the Lown arrhythmia grading system to predict death in 400 patients who were convalescing from acute myocardial infarction. ⋯ The Lown grading system failed to reveal clearly the change in VPD frequency and characteristics as a function of drug dose. We propose an alternative grading system that is not mutually exclusive or hierarchical. This grading system lacks many of the flaws of the Lown grading system and is suitable for standard multivariate analyses but, like the Lown grading system, still fails to show the relationships among ventricular arrhythmias, time, drug dose, and activity.
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American heart journal · Sep 1980
Effects of circulatory arrest and rewarming on regional blood flow during surface-induced hypothermia.
Regional blood flow and distribution of cardiac output (CO) were evaluated by the radioactive microsphere technique in rhesus monkeys during surface rewarming following the induction of deep hypothermia (20 degrees C.) under deep ether anesthesia. A comparison of animals subjected to 30 minutes of circulatory arrest and those not arrested revealed cerebral, coronary, and renal vascular resistance and flow patterns consistent with a hyperemic response to circulatory arrest at 20 degrees C. Throughout rewarming cerebral and coronary absolute flows tended to be at or above the flows noted at comparable cooling temperatures in a previous study. ⋯ CO appeared to be similar to those noted at comparable cooling temperatures until 30 degrees C. during rewarming; thereafter, CO did not fully recover to awake control levels. These data suggest that regional flow is redistributed from the carcass and renal circulations to cerebral and coronary circulations in response to hemodynamic alterations during surface rewarming. It was concluded that autoregulative responses to both circulatory arrest and hemodynamic factors are elicited during surface rewarming from deep hypothermia to 20 degrees C. with the method described.
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American heart journal · Jan 1980
Exercise-induced ventricular ectopy in children and young adults with complete heart block.
Twenty-five children and young adults with complete heart block and 50 normal control subjects were maximally exercised on a treadmill and their electrocardiograms were analyzed for the presence and degree of ventricular ectopy activity. Sixty-eight % (17 of 25) of the heart block patients and significant ventricular ectopy (frequent unifocal ectopy or worse) on exercise compared to 2% (one of 50) of the controls (p = less than 0.01). ⋯ No significant differences were found between the 14 patients with isolated "congenital" heart block, the seven with associated defects, and the four with surgically acquired block. We believe that severe ventricular ectopy is common at exercise in patients with complete heart block and they may have an increased risk for sudden death.