PubMed Health⌕ Search

Biomedical subjects

G W Vetrovec

Publications and source records attributed to G W Vetrovec.

At least 37 records · Page 2Linked to original sources
PubMed1996

Anomalous first septal perforator artery: anatomic-clinical correlates.

The interventricular septum is considered the most densely vascularized portion of the heart, containing important elements of the cardiac conduction system and providing mechanical support for both right and left ventricular function. Anatomically, this structure is perfused by the relatively small caliber anterior and posterior septal perforator branches arising from two large epicardial coronary vessels, the anterior interventricular (descending) branch of the left coronary artery and the posterior interventricular (descending) branch of the right coronary artery, respectively. In cases of significant atherosclerotic disease depriving flow in the major coronary vessels and their septal branches, an anomalous septal perforator artery can take over the task of supporting the function of the interventricular septum by supplementing essential collateral flow.

Aged↗
PubMed1994

Hemodynamic and electrophysiologic effects of first- and second-generation calcium antagonists.

The calcium antagonists currently available exert significantly different in vitro and in vivo electrophysiologic, hemodynamic, and contractile effects on cardiovascular function, mediated through differential cardiac and vascular smooth muscle responses to calcium channel blockade. These differences have important implications regarding choice of agent in specific clinical conditions, such as sinus or atrioventricular nodal disease, depressed left ventricular function, or congestive heart failure--conditions that may coexist with angina or hypertension. Recognizing and utilizing the properties of the different calcium antagonists is important to ensure maximally effective clinical outcomes. For example, in patients with hypertrophic cardiomyopathy and supraventricular arrhythmias, verapamil is singularly effective, whereas in post-myocardial infarction patients with pulmonary congestion, diltiazem may produce an added risk. Calcium antagonists of the dihydropyridine class, such as nifedipine and amlodipine, have the greatest peripheral vasoselective effects and thus the greatest potential to reduce afterload, minimizing direct left ventricular depression of contractility. Despite favorable effects of calcium antagonists, most of the agents currently available are not clearly safe in congestive heart failure and may adversely affect left ventricular function. However, newer calcium antagonists such as amlodipine are being investigated with regard to their safety in congestive heart failure.

Amlodipine↗
PubMed1994

Immediate results of interventional devices for coronary ostial narrowing with angina pectoris.

Angioplasty of aorto-ostial lesions has had suboptimal results. This study reports on the immediate results of new debulking devices (atherectomy, excimer laser) in the treatment of aorto-ostial disease. Thirty-one vessels (29 patients) with an ostial lesion treated with a new device (group I) were compared with 15 vessels (13 patients) with an ostial lesion treated with angioplasty alone during the preceding 24 months (group II). Both groups were similar in their clinical characteristics. A larger proportion of vessels in group I (64%) compared with group II (7%) had unfavorable features for angioplasty. Procedural success was similar: 28 vessels in group I (91%) and 14 in group II (93%). Among the new devices, success was also similar: atherectomy in 8 arteries (89%), rotablator in 4 (100%) and excimer laser in 17 (94%). The acute gain was more significant with new devices: absolute reduction in percent stenosis was 66% for directional atherectomy, 67% for rotational atherectomy (p = 0.016 compared with angioplasty), 52% for excimer laser (p = 0.09) and 46% for angioplasty. In group I, 2 patients (6%) required emergency bypass surgery during our early experience; no deaths or Q-wave myocardial infarctions occurred. Group II had no complications. Therefore in aorto-ostial lesions, despite a much higher prevalence of unfavorable angiographic characteristics, new devices had (1) a success rate of > or = 90%, (2) a significantly larger acute gain compared with angioplasty alone, and (3) an acceptable complication rate. Larger studies with complete angiographic follow-up are needed to assess restenosis.

Aged↗
PubMed1994

Histopathologic correlates of unstable ischemic syndromes in patients undergoing directional coronary atherectomy: in vivo evidence of thrombosis, ulceration, and inflammation.

Complex coronary morphologic abnormalities with thrombus and ulceration have been recognized in acute ischemic syndromes by angiography, angioscopy, and autopsy. However, in vivo histopathologic correlates of unstable ischemic syndromes have not been described. The purpose of this study was to characterize intracoronary lesion morphologic abnormalities by analyzing specimens excised by directional atherectomy in patients with different ischemic syndromes. Tissue specimens removed by directional coronary atherectomy of primary lesions in native vessels were matched blindly to the clinical status of 130 patients representing 43% of a consecutive directional coronary atherectomy population of 300 patients; 824 specimens (range per patient 1 to 30, mean 6.3) were obtained. Clinical subgroups were prospectively classified as recent myocardial infarction (< or = 15 days, mean 6, range 1 to 15 days), 48 patients; prolonged rest angina, 34 patients; crescendo angina, 29 patients; and stable angina, 19 patients. Shavings were prospectively analyzed for presence of thrombus, ulceration, or chronic inflammatory cells. Thrombus was observed in 33 (69%) patients with recent myocardial infarction, 17 (50%) with rest angina, 12 (41%) with crescendo angina, 7 (37%) with stable angina (p = 0.048). Plaque ulceration was identified in 12 (25%) patients with recent myocardial infarction, 4 (12%) with rest angina, 2 (7%) with crescendo angina, and 1 (5%) with stable angina (p = 0.09). Inflammatory cells were noted in the specimens of 32 (67%) patients with recent myocardial infarction, 16 (45%) with rest angina, 12 (41%) with crescendo angina, and 9 (45%) with stable angina.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1993

Usefulness of myocardial contrast echocardiography in detecting the immediate changes in anterograde blood flow reserve after coronary angioplasty.

Myocardial contrast echocardiography has revealed that successful coronary angioplasty results in an immediate decrease in the amount of collateral blood flow to the perfusion bed supplied by the dilated vessel. This information could potentially be used with pharmacologic stress in the catheterization laboratory to also assess the improvement in coronary flow reserve after angioplasty. The immediate changes in area under the time intensity curve produced by a 1 ml slow injection of sonicated albumin immediately proximal to a stenosis before and after 14 angiographically successful angioplasties was studied in 12 patients. Area under the curve was assessed before and after an 8 mg selective injection of papaverine. The changes in area under the curve were correlated with percent improvement in epicardial area stenosis. Visually successful angioplasty resulted in > 30% improvement in area under the curve after papaverine in 9 of 14 studies. There was a significant correlation between improvement in area under the curve after papaverine and percent improvement in epicardial area stenosis (r = 0.75; p < 0.01). No patient had left ventricular wall motion abnormalities after papaverine before or after angioplasty. These changes suggest that quantitatively successful angioplasty results in decreased collateral blood flow to the involved myocardium during pharmacologic stress. These improvements in coronary flow reserve cannot be predicted by visual analysis of angioplasty results.

Aged↗
PubMed1993

Assessment of thallium scintigraphy and echocardiography during dobutamine infusion for the detection of coronary artery disease.

Dobutamine infusion was performed in 16 patients following cardiac catheterization, and non-invasive assessment was performed with thallium SPECT and echocardiography. Dobutamine thallium scintigraphy was abnormal in 93% of patients with significant coronary artery disease. In addition, individual epicardial vessel involvement was identified by a corresponding perfusion defect with 88% sensitivity and 93% specificity. Dobutamine echocardiography revealed segmental wall motion abnormalities in 62% of patients with significant coronary disease. However, in six patients baseline segmental wall motion abnormalities on echocardiography improved during dobutamine infusion. Dobutamine thallium SPECT is a safe and useful test for the detection and localization of coronary artery disease. Dobutamine echocardiography is less useful in screening for coronary disease, but may detect areas of abnormally functioning myocardium having retained viability.

Adult↗
PubMed1993

Pulmonary artery hemodynamic response to proximal balloon dilatation of a large dominant right coronary artery.

The human right ventricle has a relatively low tolerance to even short periods of ischemia. During angioplasty of the right coronary artery, pulmonary artery pressure typically rises due to an increase in right ventricular afterload caused by left ventricular dysfunction during ischemia. We have presented two cases of angioplasty in the early proximal portion of a large, highly dominant right coronary artery. Pulmonary artery and systemic pressure fell during balloon inflation probably secondary to acute severe right ventricular failure, though an interaction with left ventricular dysfunction cannot be excluded. These observations do emphasize the hemodynamic and combined ventricular consequences of proximal angioplasty in a large, dominant right coronary artery, particularly in the setting of preexisting left ventricular dysfunction.

Aged↗
PubMed1993

Medical complications of cocaine: possible relationship to low plasma cholinesterase enzyme.

What predisposes some cocaine users to its complications is not known. Because cocaine is metabolized by plasma cholinesterase enzyme, we evaluated this enzyme in 14 patients with cocaine-induced complications, 11 long-term cocaine users from Bolivia, 14 persons in the United States without any documented cocaine-induced complications, and 14 subjects who have not used cocaine. The enzyme was found to be significantly lower in patients with cocaine-induced complications as compared to other groups (p < 0.05). A low level of plasma cholinesterase enzyme may predict complications from cocaine use.

Adult↗
PubMed1993

Myocardial contrast echocardiography for the assessment of coronary blood flow reserve: validation in humans.

OBJECTIVES: The aim of this study was to validate the use of myocardial contrast echocardiography to determine coronary blood flow reserve in humans. BACKGROUND: Although myocardial contrast echocardiography has been used to accurately quantify coronary flow reserve in animals, validation for its use in humans to measure flow reserve is lacking. METHODS: We analyzed the time-intensity curve from the anteroseptal region of the left ventricular short axis produced after a left main coronary artery injection of sonicated albumin before and after intracoronary administration of papaverine in 16 patients without angiographically significant coronary artery disease. The ratio of half-time of video intensity disappearance from peak intensity, variable of curve width, area under the time-intensity curve and corrected peak contrast intensity after papaverine compared with baseline were correlated with coronary flow reserve measured simultaneously with an intracoronary Doppler probe in the left anterior descending coronary artery. RESULTS: There was a strong inverse correlation with half-time of contrast washout and coronary flow reserve (r = -0.76, p = 0.0007) and a strong positive correlation between the variable of curve width (which is inversely proportional to curve width) and coronary flow reserve (r = 0.71, p = 0.002). There was a weak but significant inverse correlation between area under the time-intensity curve and coronary flow reserve (r = -0.54, p = 0.03) but no correlation between corrected peak contrast intensity and coronary flow reserve (r = -0.36, p = NS). Despite the strong correlation for the ratios for half-time of contrast washout and variable of curve width and actual coronary flow reserve measured with intracoronary Doppler probe, the transit time ratios consistently underestimated coronary flow reserve. CONCLUSIONS: Myocardial contrast echocardiography performed with left main coronary artery injections of sonicated albumin can be utilized to measure coronary flow reserve in humans. Transit time variable ratios (half-time of contrast washout and variable of curve width) derived from the time-intensity curve correlate most strongly with coronary flow reserve.

Adult↗
PubMed1993

Evaluation of the acute hemodynamic and electrophysiologic effects of intravenous amlodipine alone and in combination with a beta-blocker in patients with angina pectoris.

The acute hemodynamic and electrophysiologic effects of intravenous amlodipine (2 x 10 mg), administered either alone or on a background of beta-blocker therapy, were studied in 25 patients with angina pectoris. Hemodynamic assessments showed that amlodipine produced significant decreases in systemic vascular resistance and systemic blood pressure, and increases in stroke volume and cardiac output in both treatment groups. Electrophysiologic evaluation revealed that neither sinus node function, nor HIS ventricular conduction, were altered with amlodipine. Therefore, acute intravenous administration of amlodipine alone or in combination with a beta-blocker does not appear to compromise left ventricular performance, sinus node function, or intracardiac conduction.

Adrenergic beta-Antagonists↗
PubMed1992

Frequency and predictors of left ventricular segmental dysfunction in patients with recent rest angina.

The relation between coronary artery lesion morphology and associated segmental left ventricular (LV) dysfunction in patients with unstable angina is unclear. Fifty-two patients with angina occurring at rest who underwent cardiac catheterization within 3 days of the last episode of pain and had no enzymatic evidence for myocardial necrosis were evaluated. Coronary artery narrowings deemed responsible for the ischemic episodes were analyzed with regard to the artery involved, maximal diameter of the narrowing, presence of thrombus, and complex appearance. Time to catheterization, age, sex and electrocardiographic evidence of ischemia were also noted. Segmental LV dysfunction in the territory supplied by the "culprit lesion" was present in 58% of patients. It occurred significantly more often with lesion location in the left anterior descending coronary artery, and was less frequent with lesions in the left circumflex and ramus coronary arteries. Ischemic electrocardiographic changes were more sensitive in predicting LV dysfunction with culprit lesion location in the left anterior descending or right coronary artery. LV dysfunction could not be predicted by any other parameter analyzed. It is concluded that postischemic LV dysfunction occurs frequently in rest angina, especially when the severest narrowing is in the left anterior descending coronary artery.

Aged↗