The Canadian journal of cardiology
-
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)
-
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.
-
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.
-
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)
-
An association between rapid reversion of supraventricular tachycardia by carotid sinus stimulation and carotid sinus reflex hypersensitivity during sinus rhythm is described in a 55-year-old patient. The findings indicate that a high level of vagal tone facilitates vagal maneuvers in terminating some supraventricular tachyarrhythmias. The briskness of the response during tachycardia may also be a marker for underlying carotid sinus hypersensitivity.