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R A Oliveros

Publications and source records attributed to R A Oliveros.

14 recordsLinked to original sources
PubMed1983

Ischemia-associated intraventricular conduction disturbances during exercise testing as a predictor of proximal left anterior descending coronary artery disease.

To determine the incidence and significance of transient intraventricular conduction abnormalities occurring in association with myocardial ischemia during exercise testing, the recordings of 2,200 consecutive exercise tests were reviewed. Ten patients (0.45%) were identified as having both ischemia and intraventricular conduction abnormalities that developed transiently during the exercise test. In all 10 patients both typical angina and electrocardiographic evidence of ischemia developed during exercise. Among the 10 patients, left anterior hemiblock developed in 4, left posterior hemiblock in 2, right bundle branch block (RBBB) in 2, RBBB with left axis deviation in 1, and left anterior hemiblock progressing to complete left bundle branch block (LBBB) in 1. All 10 patients had cardiac catheterization showing significant obstruction of the left anterior descending (LAD) coronary artery at or before the origin of the first septal branch. Eight patients were treated surgically and 2 medically, all with relief of ischemic symptoms. Nine of the 10 had repeat exercise stress testing without angina or electrocardiographic evidence of ischemia and without recurrence of the transient intraventricular conduction disturbance. It is concluded that the development of transient intraventricular conduction abnormalities associated with myocardial ischemia during exercise testing is an uncommon occurrence (0.45%). When such conduction disturbances do develop, the existence of significant disease in the proximal portion of the LAD coronary artery is strongly suggested. With control of myocardial ischemia, the transient conduction disturbances during exercise are ameliorated.

Adult↗
PubMed1981

Exercise-induced myocardial oxygen supply-demand imbalance in asymptomatic or mildly symptomatic aortic regurgitation.

Left ventricular (LV) performance may remain normal in patients with LV volume overload from aortic regurgitation, but this entity results in progressive LV dysfunction. Impairment of myocardial reserve may remain undetected by current methods of assessing ventricular performance at rest, but the stress of exercise may demonstrate a reduction of myocardial reserve. To analyze the relationship between the myocardial supply and demand for oxygen in patients with aortic regurgitation, the ratio of the diastolic pressure-time index (DPTI) over the systolic pressure-time index (SPTI) was derived from recordings of pressure tracings during cardiac catheterizations in 14 patients with aortic regurgitation, and this ratio was compared with that of 24 normal subjects. The patients with aortic regurgitation had a DPTI/SPTI that fell with exercise (0.91 +/- 0.2 to 0.55 +/- 0.2) to lower values than did the ratio in the normal subjects (1.3 +/- 0.2 to 0.8 +/- 0.1) with stress. Among the patients with aortic regurgitation, a DPTI/SPTI ratio less than 0.50 with exercise identified two groups of patients that were not well separated by more common indices of severity of aortic regurgitation. The only other parameter that separated these two groups was the end-systolic volume, which is an index that reflects myocardial contractile function independent of preload. The DPTI/SPTI ratio that falls to abnormal levels with exercise may accurately reflect a failure of myocardial reserve in aortic regurgitation.

Adult↗
PubMed1981

Behavior of serum myoglobin during cardiac catheterization: concise communication.

We have studied 28 patients undergoing coronary angiography by the Judkins technique to determine whether serum myoglobin (MG) might be useful as an indicator of myocardial injury during routine cardiac catheterization and coronary angiography. MG was measured immediately before and after the procedure, and 4 hr later. The study population failed to show a rise of MG outside the normal range in spite of angina, hypotension, or severe coronary disease. Four patients premedicated with intramuscular pentobarbital (positive control) showed a consistent rise, with a range 1.5--3 times normal (p less than 0.001). We conclude that injury to myocardial or peripheral tissues occurring during coronary angiography does not raise myoglobin in venous blood above normal levels in the absence of myocardial infarction or preoperative intramuscular injection. Myoglobin, therefore, provides a useful test for the exclusion of myocardial infarction following coronary angiography.

Adult↗
PubMed1980

Echocardiographic systolic time intervals. Left ventricular performance in coronary artery disease.

The ratio of the preejection period to the left ventricular ejection time (PEP/LVET), obtained from the aortic root echocardiogram, was studied immediately before and after left ventricular (LV) cineangiography in 23 patients with documented coronary artery disease. The initial PEP/LVET ratio was inversely related to LV ejection fraction (r = -.78, P less than or equal to .001). Repeat measurements taken 60 s after angiography showed a significant decrease from a mean value of .36 +/- .13 to .27 +/- .08 (P less than or equal to .005). Furthermore, when patients were divided into those with an initial PEP/LVET value above and below 0.40, those with a higher value showed a significantly greater decrease following contrast left ventriculography (mean decrease, 0.16 vs 0.06, P less than or equal to .01). This study indicates that systolic time intervals derived from echocardiography are a reliable noninvasive measure of LV function, and that ventricular function improves following left ventriculography, with the degree of improvement being inversely related to initial function.

Adult↗
PubMed1980

Electrocardiographic aspects of acute left anterior hemiblock induced by exercise.

The intraventricular conduction time was measured during rest, exercise, and recovery in five patients who developed acute left anterior hemiblock during exercise-induced myocardial ischemia. The A QRS shifted from 58 +/- 17 degrees at rest to -66 +/- 11 degrees during exercise (p less than 0.001). The intraventricular conduction time at rest was 86 +/- 4 ms and increased to only 90 +/- 4 ms during left anterior hemiblock. Our observations suggest that the intraventricular conduction time is not always prolonged during left anterior hemiblock, particularly if this conduction abnormality is acute.

Adult↗
PubMed1979

Myocardial oxygen supply-demand ratio: a validation of peripherally vs centrally determined values.

We sought to validate that the supply-demand ratio for myocardial oxygen could be accurately measured from tracings of peripheral as well as central arterial pressure. This ratio was the ratio of the diastolic pressure-time-index (DPTI) over the systolic pressure-time index (SPTI). Sixteen patients had the peripheral DPTI/SPTI determined at cardiac catheterization by the following two different methods: (1) P1, using the mean diastolic and systolic peripheral arterial pressure and the ratio of the duration of diastole and systole; and (2) (P2, where the peak systolic and diastolic peripheral arterial pressures are used, eliminating the need for planimetric data. The results of P1 and P2 correlated closely with the central value (r = 0.96 and 0.92, respectively). We conclude that DPTI/SPTI can reliably be measured from a tracing of peripheral arterial pressure, enabling reliable continuous monitoring of this ratio.

Adolescent↗
PubMed1979

Myocardial supply-demand ratio in aortic regurgitation.

To analyze the relationship between the myocardial supply and demand for oxygen in patients with aortic regurgitation, the ratio of the diastolic pressure-time index (DPTI) over the systolic pressure-time index (SPTI) was derived from recordings of pressure during cardiac catheterization in 24 patients with aortic regurgitation, and this ratio was compared with that in 14 normal subjects and in ten patients with congestive cardiomyopathy (an ejection fraction less than 0.30). Patients with aortic regurgitation had a DPTI/SPTI of 0.75 +/- 0.06 (mean +/- SE), which was lower than in the normal subjects (1.24 +/- 0.06) and patients with cardiomyopathy (1.06 +/- 0.03) (P less than 0.001). Among the patients with aortic regurgitation, the 13 with a DPTI/SPTI below 0.70 had more severe aortic regurgitation than the 11 with a DPTI/SPTI above 0.70. Aortic regurgitation results in a reduced myocardial supply-demand ratio, as measured by the DPTI/SPTI, which is related to the severity of the valvular regurgitation and is not present in patients with left ventricular dysfunction secondary to congestive cardiomyopathy.

Adult↗
PubMed1977

Intermittent left anterior hemiblock during treadmill exercise test. Correlation with coronary arteriogram.

Two patients in whom left anterior hemiblock occurred during a treadmill exercise test were found at cardiac catheterization to have significant obstruction of the proximal portion of the left anterior descending coronary artery. After successful myocardial revascularization in one of these patients, a disturbance in conduction no longer appeared during treadmill testing. To our knowledge, this association has not been previously reported, and this finding may be a useful clinical marker for significant obstructive disease of the proximal portion of the left anterior descending coronary artery.

Adult↗