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Biomedical subjects

J H Vogel

Publications and source records attributed to J H Vogel.

At least 37 records · Page 2Linked to original sources
PubMed1977

A theoretical model of regionally ischemic myocardium.

The isometric tension development of a one-dimensional regionally ischemic muscle was analyzed theoretically. The model consist of a one-dimensional normal segment in series with a one-dimensional ischemic segment. Each segment is modeled as a three-element muscle. The inputs to the various elements, except the contractile element in ischemic segment, were obtained from published data for cat papillary muscles. To be consistent with segment length measurements on ischemic canine hearts, it was assumed that the ischemic contractile element contracted normally at the beginning of contraction and then at some tension, TM, fell behind in its rate of tension development compared to the contractile element in the normal segment. Rate of tension development of various lengths of the ischemic segment and strengths of the ischemic contractile element. At the tension, TM, the ischemic segment begins undergoing paradoxical expansion and, simultaneously, as a result of the expansion. the time derivative of the tension produced by the regionally ischemic muscle exhibits a sudden decrease.

Animals↗
PubMed1976

A simple method for calculating left ventricular functions from angiographic data using a programmable hand calculator.

The end diastolic volume and systolic ejection fraction have gained increasing acceptance as important indicators of ventricular performance. Time consuming calculations and lack of computer facilities have hindered the emergence of these calculations as a routine part of cardiac catheterization studies. The introduction of the programmable hand calculator has provided means for rapid analysis of ventricular volume data in an efficient and inexpensive manner. In this paper the step-by-step procedure for programming the hand calculator is given, as well as instructions for entering raw data and obtaining final calculations. Programs are given for both single plane and biplane cine angiographic studies.

Angiography↗
PubMed1975

Objective elaluation of bypass surgery in patients with acute coronary artery disease.

80 patients with acute coronary artery disease, including 70 patients with PIA, 8 patients with acute myocardial infarction, and 2 patients with cardiogenic shock, underwent bypass surgery. The surgical mortality rate was 1.4% in patients with PIA and during an average follow-up period of 15 months none of the patients died of cardiac disease. Ventricular function, as indicated by systolic ejection fraction and segmental wall motion, was noted to improve in many patients. Postoperative studies showed the internal mammary artery to be superior to the saphenous vein graft for left coronary bypass procedures. This was demonstrated by 100% patency of internal mammary artery grafts to the left anterior descending coronary artery. We believe that when a patient presents with one of the syndromes of acute coronary artery disease such as unstable angina, severe chest pain suggestive of infarction without infarction, status anginosis, recurrent ventricular tachycardia or acute myocardial infarction complicated by evidence of potential extension, cardiogenic shock, heart block or rupture, these patients deserve at least coronary and left ventricular cineangiographic studies with hemodynamic evaluation. Our experience to date suggests that myocardial revascularization and catheterization carry a lesser risk than that of medical treatment.

Acute Disease↗