Biomedical subjects

G S Hirsowitz

Publications and source records attributed to G S Hirsowitz.

5 recordsLinked to original sources

PubMed1989

Biventricular function during postextrasystolic potentiation in man. A study using list-mode radionuclide ventriculography.

The effects of postextrasystolic potentiation during spontaneous ventricular ectopy on both left and right ventricular function were studied in 12 patients with the aid of list-mode radionuclide ventriculography. The left ventricular ejection fraction showed a significant increase (+ 11.0 +/- 5.0%; p less than .001) with associated mild increases in end-diastolic volumes (+ 4.9 +/- 4.6; p less than .01) and significant decreases in end-systolic volumes (-13.4% +/- 7.3%; p less than .001). A more heterogeneous response was seen for the right ventricle. Right ventricular ejection increased significantly in 8/12 patients (+ 3.3 +/- 3.0%; p less than .02). Despite a large increase in end-diastolic volumes (+ 10 +/- 7.9%; p less than .001), there were only mild changes in end-systolic volumes (+ 2.2 +/- 9.0; p = NS). It is concluded that, for spontaneous ventricular ectopy in man, the increase in right ventricular ejection fraction reflects improved ventricular filling whereas the increase in left ventricular ejection fraction is linked to improved emptying.

Adult↗

PubMed1984

Right ventricular function evaluated by radionuclide angiography in acute myocardial infarction.

Radionuclide angiographic studies were performed in 26 patients with a first myocardial infarction, 11 with anterior and 15 with an inferior location. Right ventricular (RV) and left ventricular (LV) ejection fractions (EF) were determined. Mean LVEF in anterior infarctions (33.2 +/- 7.3) was lower than in inferior myocardial infarctions (59.9 +/- 10.2) (p less than 0.001). Mean RVEF in the anterior infarct group was 41.3 +/- 15.1 and in the inferior myocardial infarction group 33.7 +/- 12.8 (p = NS). RVEF was less than 40% in 11 of 15 (73%) with inferior and 7 of 11 (66%) with anterior myocardial infarction. The ratio of LVEF:RVEF was 0.84 +/- 0.19 in the anterior and 2.13 +/- 1.28 in the inferior myocardial infarction group (p less than 0.001). LVEF correlated with RVEF in patients with anterior infarcts (r = 0.77; p less than 0.05) but not in those with inferior myocardial infarction (r = 0.14). RV regional wall motion abnormalities were observed in the inferolateral zones in 10 of 15 (66%) with inferior and in none of the 11 patients with anterior myocardial infarctions (p less than 0.001). Inferoseptal wall motion abnormalities were observed in 3 of 15 (20%) with inferior and 6 of 11 (56%) with anterior myocardial infarctions (p = NS). RV dysfunction in the inferior infarctions is probably an expression of primary RV dysfunction rather than secondary to LV dysfunction. RV dysfunction was proportional to LV dysfunction in the anterior infarction group and was often accompanied by RV septal contraction abnormalities.

Aged↗

PubMed1984

Sequential radionuclide angiographic assessment of left and right ventricular performance and quantitative thallium-201 scintigraphy following acute myocardial infarction.

Sequential changes in radionuclide angiographic measurement of left and right ventricular performance and quantitative thallium-201 scintigraphy were studied in 20 patients sustaining their first acute myocardial infarction (AMI). The studies were performed on the average 29.4 hours and 9.4 days after hospital admission. Anterior infarction had greater impairment of left ventricular (LV) performance in terms of ejection fraction and percentage of abnormal contraction area in addition to larger thallium-201 perfusion defects. At the time of the late study evidence of thallium-201 perfusion of infarcted area was seen in 14 of 20 patients, five of whom demonstrated improvement of regional wall motion. The remaining patients in the reperfused group and all of the patients in the nonperfused group failed to show evidence of LV functional improvement. This study indicates that reperfusion as measured by thallium-201 scintigraphy does occur spontaneously in 70% of patients with AMI and only in those patients with established reperfusion is there any potential for improvement in LV performance.

Coronary Circulation↗

PubMed1983

Comparison of radionuclide and enzymatic estimate of infarct size in patients with acute myocardial infarction.

A comparison was made of the estimated size of the myocardial infarction occurring in 26 patients with a first infarction using creatine kinase (CK) enzyme release between radionuclide gated blood pool measurement of total and regional ventricular function and thallium-201 scintigraphic measurement of myocardial perfusion defects. Creatine kinase estimates of infarct size (enzymatic infarct size) correlated closely with the percent of abnormal contracting regions, left ventricular ejection fraction and thallium-201 estimates of percent of abnormal perfusion area (r = 0.78, 0.69 and 0.74, respectively, p less than 0.01). A close correlation also existed between percent abnormal perfusion area and percent of abnormal contracting regions (r = 0.81, p less than 0.01) and left ventricular ejection fraction (r = 0.69, p less than 0.01). Enzymatic infarct size was larger in anterior (116 +/- 37 CK-g-Eq) than inferior (52 +/- 29 CK-g-Eq) myocardial infarction (p less than 0.01) and was associated with significantly more left ventricular functional impairment as determined by left ventricular ejection fraction (33 +/- 7 versus 60 +/- 10%) (p less than 0.01) and percent abnormal perfusion area (58 +/- 14 versus 13 +/- 12) (p less than 0.01). No significant correlation was observed between enzymatic infarct size and right ventricular ejection fraction. These different methods of estimating infarct size correlated closely with each other in these patients with a first uncomplicated myocardial infarction.

Adult↗

PubMed1978

Hemiplegia and the billowing mitral leaflet syndrome.

Four young patients presenting with major neurological episodes and with coexisting prolapsing mitral valve are described. An attempt at correlating the two entities is made. The neurological complications of prolapsing mitral valve are stressed.

Adolescent↗