The Canadian journal of cardiology
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While abnormalities of right ventricular hemodynamics are known to affect interventricular septal position and shape, their effect on left ventricular shape and possibly function have been less well studied. Accordingly, the two-dimensional echocardiographic appearance of the left ventricle was studied in 11 patients with right ventricular volume overload, 16 with right ventricular pressure overload, nine with combined pressure and volume loads of the right heart and 17 normal control subjects. An index of left ventricular shape (SI) was calculated from end diastolic, mid systolic and end systolic left ventricular short axis area (A) and circumference (C) taken at the level of the tips of the mitral leaflets, using the formula SI = 4 pi A/C2. ⋯ Combined pressure and volume overload produced left ventricular deformation during the entire cycle which was of an order of magnitude more severe than any other group (SI = 0.69, 0.70 and 0.65, at end diastole, mid and end systole, respectively). The shape index at end systole showed an inverse correlation with the relative right-to-left ventricular systolic pressure ratio (P = 0.001, r = 0.76). It is concluded that left ventricular configuration is affected by right ventricular hemodynamics.(ABSTRACT TRUNCATED AT 250 WORDS)
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Over a one year period (1979 to 1980) all cardiac admissions to the coronary care units (CCU) and all intensive care unit (ICU) overflow admissions in Hamilton, Ontario, a city of approximately 375,000 people, were documented. Mortality status was determined one year following admission. There were 2004 individuals with either acute myocardial infarction (810), unstable angina (811) or other chest pain (783) as their first CCU/ICU admitting diagnosis that year. ⋯ For acute myocardial infarction, female mortality was greater than male mortality overall and in all but one age category. Mortality following acute myocardial infarction and unstable angina was strongly related to age. Repeat CCU/ICU admission occurred in 24% of acute myocardial infarction, 28% of unstable angina and 15% of other chest pain, while a total of death or nonfatal CCU/ICU readmission occurred in 31% of acute myocardial infarction, 32% of unstable angina and 17% of other chest pain.
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Comparative Study Clinical Trial Controlled Clinical Trial
A prospective trial of new versus refurbished cardiac pacemakers: a Canadian experience.
Pacemaker reimplantation in the same patient is common, and pacemaker transplantation or reuse in a second patient has been reported. No report prospectively compares the long term costs, the impact of reuse on the number of pacemakers implanted, the pacemaker related complications, the types of patients selected and the patient survival of those who receive new versus a refurbished pacemaker. The authors implanted 70 pacemakers of which 75% (52) were new and 25% (18) were refurbished. ⋯ After three years the cumulative probability of survival in the new group tended to be higher (P = 0.08) with a mean (SE) of 0.62 (0.12) versus 0.44 (0.15). New and refurbished pacemakers are similar with respect to pacemaker related survival and complications. Refurbished pacemakers effect a major reduction in pacemaker costs while maintaining health care standards.
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Between 1979 and 1985, 552 Ionescu-Shiley valves were implanted in 511 patients. The Hancock valve was implanted in 122 patients (129 valves) between 1982 and 1983. Sixty percent of procedures were isolated aortic valve replacements. ⋯ Actuarial survival for the former was 73 +/- 4% at 72 months, and 65 +/- 14% for Hancock valves at 60 months. The frequency of major events during follow-up (thromboembolism, anticoagulant related hemorrhage, bland perivalvular leak and prosthetic valve endocarditis) were similar, but the frequency of primary tissue valve failure was markedly different for the two valves (1.1% per patient-year for Ionescu-Shiley valves and 5.9% for the Hancock valve). The mean interval to replacement of an Ionescu mitral prosthesis was significantly shorter (23.4 months) than for replacement of an aortic prosthesis (42 months) while the mean interval to replacement of an Ionescu aortic and/or a Hancock aortic or mitral were all similar.(ABSTRACT TRUNCATED AT 250 WORDS)
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Electrophysiologic studies were performed in nine survivors of out-of-hospital cardiac arrest who had no overt heart disease on clinical, hemodynamic and angiographic evaluation. Cardiac arrest occurred during sedentary activity in seven patients and during exercise in two; no patient was on antiarrhythmic drugs at the time of cardiac arrest. Twenty-four hour ambulatory electrocardiographic monitoring demonstrated premature ventricular beats in four patients (44%). ⋯ Of the four patients with noninducible sustained VT or VF, three received no antiarrhythmic therapy and one was given a beta-blocker. None had recurrent cardiac arrest or symptomatic VT after an average follow-up of 17 months (range 13 to 20 months). Thus, inducibility of sustained VT or VF provided a reliable end point for long term antiarrhythmic therapy and noninducibility identified a subset of patients that had an excellent prognosis without specific antiarrhythmic therapy.(ABSTRACT TRUNCATED AT 250 WORDS)