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Biomedical subjects

P Rigo

Publications and source records attributed to P Rigo.

At least 109 records · Page 6Linked to original sources
PubMed1981

Prognostic value of thallium-201 stress myocardial scintigraphy with exercise ECG after myocardial infarction.

The prognostic value of stress electrocardiogram and thallium-201 stress myocardial scintigraphy was analyzed in 224 patients 3 months after a myocardial infarction; both techniques allowed an adequate stratification based on the presence of ST depression or multivessel disease. Combining stress electrocardiogram and stress myocardial scintigraphy data improved the prognostic ability, particularly in patients who associated multivessel disease and ST depression.

Aged↗
PubMed1981

Premature opening of the pulmonary valve in right ventricular myocardial infarction.

An echocardiogram performed in a patient with a large right ventricular infarction reveals a premature opening of the posterior leaflet of the pulmonic valve. This opening appears initiated by the atrial contraction and its clinical and pathophysiological significance is discussed. We conclude that perturbations of the pulmonary valvular motion can occur during right ventricular infarction and reflect a profound alteration in phasic right ventricular flow.

Diastole↗
PubMed1980

Quantification of aortic valvular regurgitation in dogs by nuclear imaging.

Radionuclide gated cardiac blood pool (GBP) imaging was used to quantitatively assess the severity of acute aortic valvular regurgitation produced experimentally in 10 anesthetized dogs. Right ventricular (RV) and left ventricular (LV) stroke counts (end-diastolic minus end-systolic counts in RV and LV regions of interest) were used as indices of the stroke volumes of the two ventricles. Regurgitant fraction (RFGBP) was derived by assuming that an excess of LV stroke counts compared to RV stroke counts was due to regurgitant flow: RFGBP = LV stroke counts - RV stroke counts/LV stroke counts X 100. Regurgitant fraction (RFEMF) was also estimated directly from an electromagnetic flowmeter (EMF) on the ascending aorta. Mean RFEMF was 55.8 +/- 17.9% (+/-SD). Close agreement was found between regurgitant fractions measured by GBP and EMF (RFGBP = 1.09, RFEMF - 4.7%, r = 0.88, p less than 0.001, SEE = 9.98%). The severity of regurgitation from blood pool images also correlated closely with aortic pulse pressure (r = 0.89) and the length of the tear in the aortic valve (r = 0.84). These results suggest that blood pool imaging may be sueful for noninvasive quantification of regurgitant flow in patients with valvular insufficiency.

Acute Disease↗
PubMed1979

Monitoring ventricular function at rest and during exercise with a nonimaging nuclear detector.

A portable nonimaging device, the nuclear stethoscope, for measuring beat to beat ventricular time-activity curves in normal people and patients with heart disease, both at rest and during exercise, is being developed and evaluated. The latest device has several operating modes that facilitate left ventricular and background localization, measurement of transit times and automatic calculation and display of left ventricular ejection fraction. The correlation coefficient of left ventricular ejection fraction obtained with the device and with a camera-computer system was 0.92 in 35 subjects. During bicycle exercise the ejection fraction in 15 normal persons increased from 44 to 64 percent (P less than 0.001), whereas among 12 patients with heart disease it was unchanged in 5 and decreased in 7.

Adult↗
PubMed1979

Instantaneous transmitral blood flow and anterior mitral leaflet motion in man.

Transmitral blood flow was measured in man by numerical differentiation of left ventricular volume as a function of time in 11 patients undergoing cardiac catheterization. Using this technique, transmitral blood flow may be studied in a variety of pathologic states without the need for surgically introduced flowmeters. Just before left ventriculography, echocardiography of the mitral valve was performed. The pattern of transmitral blood flow was strikingly similar to the diastolic movement of the anterior mitral leaflet. At any equivalent diastolic filling time, the percent of the integrated area beneath the curve inscribed by the diastolic anterior mirtal leaflet echoes closely approximated the percent of stroke volume which had entered the left ventricle. This observation supports the hypothesis that mitral leaflet motion accurately reflects transmitral flow. Consequently, at a given time during diastole, the relative velocity of transmitral flow and the percent of the stroke volume which has entered the left ventricle may be approximated noninvasively from the anterior mitral leaflet echogram.

Adult↗
PubMed1979

Measurement of aortic and mitral regurgitation by gated cardiac blood pool scans.

A simple, noninvasive radionuclide technique which measures the severity of valvular regurgitation has been developed. The technique compares right and left ventricular stroke volume indices (change in counts between diastole and systole over the left and right ventricles) from 45 degrees LAO gated cardiac blood pool scans. In 14 control subjects, the left-to-right ventricular stroke index ratio was near unity (1.15 +/- 0.15 [SD]). In 26 patients with mitral and/or aortic regurgitation it was larger (range 1.36--5.30, mean 2.44). Comparison between the stroke index ratio and qualitative angiographic estimates of regurgitation revealed good agreement (F = 45.5, p less than 0.001). Gated cardiac blood pool scans permit noninvasive assessment of the severity of valvular regurgitation.

Adult↗
PubMed1976

Gallium-67 myocardial imaging for the detection of bacterial endocarditis.

Eleven patients with a clinical diagnosis of bacterial endocarditis underwent scintillation scanning of the precordial region 2-7 days after the intravenous administration of 3 mCi of gallium-67 citrate. Seven had positive scans, 3 of which were confirmed by postmortem imaging at autopsy. Serial images revealed the scans to be frequently negative at 48 hours and positive from 3 to 8 days following injection. Uptake was not seen in the region of the myocardium 48 hours or longer after the injection of 15 patients without endocarditis used as controls.

Adult↗
PubMed1975

The combined use of Gated Cardiac Blood Pool Scanning and Myocardial Imaging with Postassium-43 in the Evaluation of Patients with Myocardial infarction.

Fourteen patients with transmural myocardial infarction were studied by gated cardiac blood pool scanning (to determine regional ventricular function) and 43-K myocardial imaging (to determine the regional distribution of myocardial perfusion). An akinetic area on the gated scan and an area of decreased tracer concentration on the 43-K image were detected. The area of reduced 43-K concentration averaged 33.5% of the left ventricular circumference which correlated (r = 0.74, p less than 0.01) with the area of infarction determined by the zone of akinesis, 34.2% of left ventricular circumference. The extent of akinesis and left ventricular ejection fraction were significantly different in those patients with left ventricular failure than in those without failure.

Adult↗
PubMed1975

Hemodynamic and prognostic findings in patients with transmural and nontransmural infarction.

One hundred and eleven patients with transmural (TMI) and 49 with nontransmural myocardial infarction (NTMI) underwent hemodynamic investigation within 24 hours of onset of symptoms. Patients with NTMI were subdivided into those with ST-segment or T-wave changes alone with a normal QRS complex (NTMI-A) and a group with QRS abnormalities that did not satisfy the criteria for TMI (NTMI-B). Those with TMI had a significantly higher peak creatine phosphokinase (CPK) than those with NTMI: 840 plus or minus 99 and 336 plus or minus 69, respectively, P smaller than 0.05. There was not difference in peak CPK between those with NTMI-A and B. The incidence of arrhythmias and cardiac failure, and routine hemodynamic findings except for left ventricular filling pressure were similar in those with TMI and NTMI. There was not significant difference in in-hospital mortality between those with TMI (22%) and NTMI (33%). There was however a significant difference in in-hospital mortality between those with NTMI-A (0%) and NTMI-B (27%, P smaller than 0.05). The late mortality in those surviving their initial hospitalization was also not different between those with TMI (18%) and NTMI (19%) during a mean follow-up period of 20.2 months. In contrast to the in-hospital mortality those with NTMI-A had a late mortality similar to those with NTMI-B and those with TMI.

Arrhythmias, Cardiac↗
PubMed1975

Right ventricular dysfunction detected by gated scintiphotography in patients with acute inferior myocardial infarction.

Twenty-seven patients with acute myocardial infarction not complicated by cardiogenic shock and ten normal volunteers were studied with gated cardiac blood pool scans. The ratio right vetricular area/left ventricular area (RVA/LVA) determined from the left anterior oblique end-diastolic scans was examined. The ratio was 1.11 +/- .06 in the normal volunteers. In patients with anterior infarction the ratio fell to 0.75 +/- .12 (P less than .05) due to left ventricular enlargement. In those with inferior infarction the ratio was 1.12 +/- .23 which was greater than in those with anterior infarction (P less than .05) due to enlargement of both the left and right ventricles. Six patients with cardiogenic shock, three with inferior and three with anterior infarction were studied. The three with anterior infarction had left ventricular enlargement and a decrease in the ratio of RVA/LVA to 0.62 while the three with inferior infarction had an increase in the ratio to 2.05 suggesting right ventricular dilatation and dysfunction. These studies suggest a high incidence of right ventricular dysfunction in patients with inferior myocardial infarction.

Aged↗