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Biomedical subjects

S Genth

Publications and source records attributed to S Genth.

12 recordsLinked to original sources
PubMed1998

Comparison of antiplatelet effects of aspirin, ticlopidine, or their combination after stent implantation.

BACKGROUND: This study was performed to analyze the influence of either aspirin, ticlopidine, or their combination on platelet activation and aggregation parameters after stent implantation. METHODS AND RESULTS: Sixty-one patients with successful implantation of a single Palmaz-Schatz stent in a native coronary artery were randomly assigned to either group A (aspirin 300 mg/d+ticlopidine 2X250 mg/d), group B (ticlopidine 2X250 mg/d), or group C (aspirin 300 mg/d). Platelet activation was evaluated on days 1, 7, and 14 by flow cytometry measurement of expression of CD62p (p-selectin) and the binding of fibrinogen to the platelet surface glycoprotein IIb/IIIa receptor. Platelet aggregation was induced by addition of ADP or collagen. Differences between treatment groups were compared by ANOVA. Between days 1 and 14, we observed a significant decrease in collagen-induced platelet aggregation in group A (62.2+/-2.5% versus 36.9+/-3.1%), whereas an increase was seen in group B (58.3+/-2.5% versus 67.7+/-3.2%) and no change was seen in group C (P<.0001). The ADP-induced aggregation declined significantly in group A (74.7+/-1.4% versus 55.3+/-2.6%), whereas a delayed reduction was seen in group B (72.0+/-3.0% versus 52.6+/-4.2%) and no change was seen in group C (P=.0017). The CD62p expression declined significantly in groups A (68.2+/-2.7% versus 41.3+/-2.7%) and B (64.8+/-2.9% versus 39.3+/-3.5%) but not in group C (P<.0001). Moreover, the fibrinogen binding decreased significantly in group A (61.0+/-4.3% versus 36.3+/-4.2%) and with delay in group B (58.3+/-2.2% versus 39.4+/-3.0%), whereas no alterations were seen in group C (P=.012). CONCLUSIONS: Our results demonstrate synergistic and accelerated platelet inhibitory effects of ticlopidine plus aspirin in patients after stent implantation compared with a monotherapy with either ticlopidine or aspirin alone.

Angioplasty, Balloon, Coronary↗
PubMed1996

The influence of Albunex on the pulmonary circulation in patients with pulmonary hypertension or left heart failure.

To determine the safety of the ultrasound contrast agent Albunex, its influence on right and left heart haemodynamics in patients with pulmonary artery hypertension or left heart failure was assessed after intravenous injection. Patients with a left ventricular ejection fraction smaller than 40% or a systolic pulmonary artery pressure greater than 40 mmHg received 0.08 and 0.22 ml.kg-1 Albunex and 10 ml albumin in random order during right heart catheterization and transthoracic echocardiography. Right atrial, systolic and diastolic pulmonary artery and capillary wedge pressures were measured at 3 min and 5 min and cardiac output at 5 min after the intravenous injection of Albunex and control. The mean differences of pre- and postinjection values and their confidence intervals were tabulated and significance was anticipated if the confidence interval did not include 0. Significant changes to pre-injection values could be observed in diastolic pulmonary artery pressure 5 min after the injection of albumin and 0.08 ml.kg-1 Albunex, and in right atrial pressure 5 min after the injection of 0.22 ml.kg-1 Albunex only. Since intermediate opacification of the left ventricle was seen in only four patients with 0.22 ml.kg-1 Albunex, in the patients studied higher doses of Albunex and their safety need to be assessed.

Albumins↗
PubMed1996

[Comparison of NYHA classification with cardiopulmonary function in patients with chronic heart failure].

In this study a correlation was sought between the NYHA class, the results of cardiopulmonary exercise testing (CPX) and the ejection fraction (EF) measured by echocardiography and scintigraphy. Of 36 patients enrolled, CHF in 20 patients was due to CAD and in 16 patients due to DCM. The NYHA class was determined independently by two cardiologists who were blinded to the CPX, echocardiography or scintigraphy results. Sixteen patients were classified as class II and 20 as class III. As a control, 23 patients without cardiopulmonary disease were examined. The CPX was done according to a ramp protocol with continuous measurement of respiratory gases, maximal oxygen consumption (VO2-max) and oxygen consumption at the anaerobic threshold (VO2-AT). A correlation (p = 0.0425) between the NYHA classification and the Weber classification for VO2-AT was found. There was no correlation for VO2-max. VO2-AT was significantly higher in NYHA II patients as compared to NYHA III patients. No significant difference was seen in relation to the VO2-max. In comparison to the normal group, the VO2-AT and VO2-max were significantly lower in NYHA II and III patients. There was no significant correlation between VO2-AT and EF, VO2-max and EF, or between NYHA class and EF. During a 16-month follow-up period lethality was 8/14 patients with VO2-AT < 10 ml/kg/min. Although the NYHA classification provides a valid method for determining the prognosis of CHF patients, if feasible, the CPX examinations should be used to provide updates of the disease progress.

Adult↗
PubMed1996

[Polymer microparticles for right and left heart echocardiography and imaging myocardial perfusion after peripheral vein injection].

It is conceivable that a stable ultrasound contrast agent could be used for reproducible right and left heart echocardiography and myocardial visualization after intravenous injection. Microparticles from different polymers and preparation procedures were screened in six dogs leading to one superior agent with reproducible high quality echo contrast in doses of 1 mg/kg. This special agent is based on condensates of aspartic acid, ethanolamine and decanoic acid. Out of this material particles were formed with an average diameter of 2 micrometers. The easily suspendable particles were used for the following studies in a dose of 1 mg/kg intravenously in eight pigs. Maximal video intensity averaged 116 +/- 42 relative intensity units (IU) in the right, 137 +/- 42 IU in the left ventricle, 42 +/- 7 in the normally perfused and 11 +/- 2 in the hypoperfused myocardium after circumflex ligature. The area under the intensity curve was 1942 +/- 100 IUxs in the right, 2452 +/- 1291 IUxs in the left ventricle, 518 +/- 124 in the normally perfused and 202 +/- 94 in the hypoperfused myocardium after circumflex ligature. There was no change of heart rate, central arterial or pulmonary artery pressure during and after the injections. There was also no loss of echo intensity during the passage of contrast material through the heart due to systolic pressure. The described agent can be used for the opacification and ultrasonic visualization of the right and left heart as well as normally and hypoperfused myocardium without visible side-effects in animal studies.

Animals↗
PubMed1994

Left atrial thrombi despite anticoagulant and antiplatelet therapy.

To investigate risk factors for embolization in patients with echocardiographically detected left atrial thrombi and to evaluate thrombus development, we examined 29 patients with transesophageal and transthoracic echocardiography at two points during a follow-up of 18 months. We compared patients with a history of possible arterial embolization (n = 13) with those without (n = 16) in regard to age, gender, left atrial dilatation, localization of the thrombus in the left atrial cavity, spontaneous echo contrast, and atrial fibrillation. Eight patients were treated with aspirin, 20 with phenprocoumon. Only left atrial spontaneous contrast was associated with thromboembolism (10/15 patients with spontaneous contrast experienced arterial embolism; p = 0.038). In six patients arterial embolism occurred after thrombus detection (14% per patient per year). Four of these patients were treated with phenprocoumon, two with aspirin. At reexamination, one thrombus was detected in the patient without anticoagulant treatment and one thrombus was detected in the 8 patients treated with aspirin (13%), compared with ten thrombi detected in the 20 patients (50%) treated with phenprocoumon (p = NS). In 17 patients no thrombus was seen at reexamination. Since only 2 patients had undergone thrombectomy and 3 experienced arterial embolism during follow-up, thrombi disappeared under medical therapy in 12 patients. Patients with left atrial thrombi have a high risk of arterial embolization despite proper anticoagulative or antiplatelet treatment. Embolization occurs significantly more often if spontaneous echo contrast can be visualized. Left atrial thrombi can be reduced in size by the administration of antiplatelet and anticoagulative agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Contrast echocardiography of the left ventricle an independent predictor of pulmonary artery pressure?

To test the hypothesis that left heart opacification is dependent on pulmonary artery pressure, we analyzed consecutively 12 patients with normal and 8 patients with abnormal pulmonary artery pressure with a new lung capillary stable echo contrast agent. Patients underwent contrast echocardiographic examination within 6 hours before right and left heart catheterization with 200 mg/ml and 400 mg/ml SHU 508A intravenously. The mean pulmonary artery pressure was 15.4 mmHg in the patients with normal pulmonary artery pressures and 46.4 mmHg in the patients with pulmonary hypertension (p < 0.000). Echocardiograms were video-intensitometrically analyzed for intensity maximum (MAX), half-time of video-intensity decay (T1/2), area under the intensity curve (AUC) in the right and left ventricle and transit time from left to right heart (TT). Patients with normal pulmonary artery pressure showed sufficient left heart opacification, in the left ventricle MAX was 37 +/- 15 IU, AUC measured 653 +/- 463 IUxs and T1/2 was 4.4 +/- 2.6 s, while patients with elevated pulmonary artery pressure showed no significant left heart opacification. In the left ventricle MAX was 8 +/- 10 IU (p = 0.006), AUC measured 66 +/- 108 (p = 0.003) and T1/2 was 2.0 +/- 2.0 s (p = 0.041). TT was significantly increased in patients with elevated pulmonary artery pressure (11.8 +/- 4.6 s versus 6.5 +/- 2.8 s in patients with normal pulmonary artery pressure, p = 0.005). Thus, elevated pulmonary pressure has a significant impact on left heart opacification, which may be used for diagnostic purposes.

Adult↗
PubMed1994

[Transthoracic and transesophageal follow-up in patients with left atrial thrombosis].

The embolic risk and changes of thrombus location and size were investigated in 29 consecutive patients with echocardiographically proven thrombi in the left atrium. Inclusion criteria were the visualization of a left atrial thrombus using transesophageal echocardiography. Transesophageal follow-up echocardiograms were performed at a mean period of 18 months. In this period 6 cases of embolism were observed at an interval of 20 days to 26 months after the detection of thrombus. Thus, the embolic rate was 14% per patient year. All patients received phenprocoumon (n = 4) or aspirin at the time of embolism. Furthermore, in two patients after cardiac thrombectomy left atrial thrombi were seen again although patients were treated with anticoagulants. On the other hand, in 12 patients (5 received oral anticoagulation, 2 received aspirin) thrombi completely resolved. It can be concluded from these data, that the majority of patients receiving anticoagulation profit from this therapy, however, a complete protection against arterial embolism or reoccurrence of thrombi cannot be reached. Left atrial spontaneous echo contrast was the only risk factor significantly associated with thromboembolism in patients with left atrial thrombi.

Aged↗
PubMed1993

Diagnosis of papillary muscle rupture after acute myocardial infarction by transthoracic and transesophageal echocardiography.

The sensitivity of transthoracic echocardiography to visualize the structural abnormality of papillary muscle rupture (PMR) after acute myocardial infarction can be anticipated to average about 50%; therefore, we evaluated five patients exhibiting the condition with both transthoracic and transesophageal echocardiography. The use of the two imaging techniques resulted in the fact that no instance of PMR was missed. Using transthoracic echocardiography in two patients and transesophageal echocardiography in four, the ruptured papillary muscle was visualized directly. Mitral insufficiency as an indirect sign was observed in all patients. In one patient the papillary muscle rupture developed in a mitral valve previously affected by endocarditis. All patients underwent mitral valve replacement and coronary artery bypass grafting. The diagnosis was confirmed at surgery in all patients. Four patients died in hospital, the fifth 5 months later. We recommended that transesophageal echocardiography be performed in patients with suspected PMR if transthoracic echocardiography does not provide an unequivocal diagnosis.

Aged↗
PubMed1993

Transthoracic and transesophageal echocardiography to diagnose ventricular septal rupture: importance of right heart infarction.

BACKGROUND: Rapid and accurate diagnosis of ventricular septal rupture (VSR) remains difficult, and the monitoring of hemodynamic deterioration is a prerequisite for the institution of adequate therapy. The timing of surgical repair is a matter of controversy. METHODS: Transthoracic, transesophageal, color Doppler, and contrast echocardiography were evaluated in 17 patients with VSR in whom the diagnosis was confirmed by catheterization, surgery, or necropsy. RESULTS: Routine transthoracic echocardiography visualized VSR in four out of 17 patients and, with additional views, in 12 out of 17 patients. Color Doppler echocardiography identified the rupture in 15 out of 16, and contrast echocardiography in 11 out of 11 patients. VSR was identified using transesophageal echocardiography in six out of nine patients, and using color Doppler and contrast echocardiography in all patients. Eight out of 10 patients who developed right heart myocardial infarction (RMI) died, whereas all patients without RMI survived (P = 0.0070). Similarly, eight out of 10 patients with shock died, whereas all patients without survived (P = 0.0070). Shock occurred more often in patients with RMI (eight out of 10) than in patients without (two out of six). All patients with both RMI and shock died, whereas those without both conditions survived (P = 0.0002). CONCLUSION: Modern echocardiography is the method of choice in the diagnosis of VSR. Right ventricular function should be evaluated in patients with VSR because patients with RMI are at high risk of hemodynamic deterioration, with poor outcome. RMI, visible as abnormal wall motion, was identified better with transesophageal than with transthoracic echocardiography.

Aged↗
PubMed1993

[Diastolic flow analysis of the left ventricle after myocardial infarct].

The diastolic function of the left ventricle was investigated in 12 normal young volunteers, 10 older volunteers, 10 patients without evidence of coronary artery disease, 26 patients with inferior wall and 19 patients with anterior wall infarction at eight locations of the total circumference of the left ventricle using pulsed wave Doppler. The ratio of early diastolic inflow (Vmax E) to the maximal velocity of atrial contraction (Vmax A) was determined. Furthermore, the delay between the end of electrical diastole until the end of the A-wave of the pulsed Doppler was measured. The results were compared with a clinically used marker of myocardial ischemia, treadmill exercise testing. The E/A ratio was 2.03 +/- 0.51 in normal volunteers, 1.16 +/- 0.41 in older volunteers, 1.41 +/- 0.59 in patients without evidence for coronary artery disease, 1.28 +/- 1.13 in patients with inferior and 1.08 +/- 0.41 in patients with anterior wall infarction (p = 0.020 ANOVA). The diastolic delay at the apex was 47.3 +/- 8.9 ms in normal volunteers, 78.3 +/- 8.3 ms in older volunteers, 79.1 +/- 13.7 ms in patients without coronary artery disease, 109.1 +/- 12 ms in patients with inferior and 169.5 +/- 18.8 ms in patients with anterior wall infarction (p = 0.000 ANOVA). There was a correlation between the latter parameter of delay and the amount of pathological wall segments at wall motion analysis (r = 0.61, p = 0.007). In two patients with anterior myocardial infarction (11%) with significant diastolic delay intraventricular thrombi developed consecutively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Left ventricular volume determination using Albunex.

The aim of this study was to assess the ability of intravenous injection of Albunex to improve left ventricular volume determination in patients with various cardiac diseases. It is conceivable that the intravenous injection of microbubbles could improve echocardiographic left ventricular border delineation leading to improved interobserver variability. Echocardiograms were obtained during simultaneous intravenous injection of 0.08 and 0.12 ml/kg Albunex (four-chamber view). Within 6 hours after the recording of the contrast echocardiograms routine left heart angiography was performed. Volumes were measured using the slice method in native and contrast echocardiograms as well as in the angiograms by two independent investigators. The mean differences of angiographic-native echocardiographic and angiographic-contrast echocardiographic volumes (ml) as well as the calculated ejection fraction and their confidence intervals were tabulated and significance was anticipated if the confidence interval did not include zero. Significant changes to angiographic values could be observed concerning end-diastolic, echocardiographic, and contrast echocardiographic volumes at end diastole and end systole, while ejection fractions were similar. Differences between observers were significantly smaller in the contrast echocardiographic images than in the native echocardiographic images. Albunex led to a significantly decreased interobserver variability.

Adult↗