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G Hahalis

Publications and source records attributed to G Hahalis.

11 recordsLinked to original sources
PubMed2002

Right ventricular cardiomyopathy in beta-thalassaemia major.

AIMS: To evaluate right ventricular function in patients with beta-thalassaemia major and congestive heart failure. Background In patients with beta-thalassaemia major a high incidence of cardiac involvement still exists despite improved prognosis with chelation therapy. Development of severe right heart failure is common and has been attributed to pulmonary hypertension secondary to lung haemochromatosis. However, the possibility of direct right ventricular myocardial involvement in the absence of significant pulmonary hypertension has not been adequately investigated. METHODS: Twenty-nine consecutively screened patients with beta-thalassaemia major and congestive heart failure were investigated by Doppler echocardiography, right ventricular first-pass radionuclide examination and cardiac catheterization. Haemodynamic data were obtained both before and after volume loading. A control group of 39 patients with beta-thalassaemia major, free from cardiac disease, and matched for age, gender, body surface area and heart rate was used for comparison. A subset of the control thalassaemic group (n=15) underwent both radionuclide and haemodynamic assessment. RESULTS: The majority of patients were on non-optimal chelation therapy. Only two of 29 patients were found to have cor pulmonale. One other patient suffered from constrictive pericarditis. A restrictive filling pattern in both ventricles and left ventricular systolic dysfunction were evident in the other 26 patients. Pulmonary artery pressure (systolic, 33+/-8 vs 27+/-5 mmHg, P<0.05) and pulmonary vascular resistance (114+/-56 vs 65+/-29 dynes. s. cm(-5), P<0.01) were only mildly elevated in the heart failure group. After volume challenge, cardiac output remained unchanged although the increments of ventricular filling pressures were significant (Deltaright atrial: 4.8+/-2.2 mmHg, P<0.05; Deltapulmonary capillary wedge: 5.6+/-2.9 mmHg, P<0.05) and correlated with each other (r=0.69;P<0.001) in heart failure patients, suggesting pericardial constraint and ventricular interaction. In these patients compared with the control thalassaemic group, a lower right ventricular ejection fraction (29%+/-9 vs 59%+/-6, P<0.0001) without correlation with pulmonary artery pressures was found. Haemodynamically significant right ventricular dysfunction defined as mean right atrial pressure >10 mmHg and ratio of mean right atrial-to-capillary wedge pressure >0.8 was evident in 15 of the 26 patients (58%), all with severe symptoms, representing three fourths of the patients in functional class III and IV. Simultaneous pressure recordings in six of these 15 patients showed equalization of ventricular end-diastolic pressures within 5 mmHg. CONCLUSION: The majority of patients with beta-thalassaemia major and severe congestive heart failure demonstrated a unique haemodynamic pattern similar to that described in predominant right ventricular infarction, indicating severe right ventricular cardiomyopathy in addition to left ventricular dysfunction. The incidence of cor pulmonale as a cause of right heart failure seems to be much lower than previously hypothesized.

Adult↗
PubMed2001

Right ventricular diastolic function in beta-thalassemia major: echocardiographic and clinical correlates.

BACKGROUND: Cardiac hemochromatosis remains the most frequent cause of death in beta-thalassemia major. Previous studies suggest an important right ventricular (RV) contribution to cardiac morbidity and mortality. Studies with Doppler echocardiography have shown contradictory results regarding left ventricular (LV) filling, whereas the RV filling characteristics have not been studied yet. We prospectively studied the pattern of RV filling and investigated echocardiographic and clinical correlates during baseline and follow-up examinations in patients with beta-thalassemia major. METHODS AND RESULTS: The study included 79 patients, aged 24.2 +/- 8.0 years, with homozygous beta-thalassemia major without symptoms of heart failure with normal LV function and 51 healthy control subjects, matched for age, sex, and body surface area. Doppler echocardiographic indexes of systolic and diastolic ventricular function were assessed. Hemodynamic measurements were obtained in 8 patients by right heart catheterization. An abnormal RV relaxation pattern was evident in the patient group. The LV filling characteristics indicated increased preload without abnormal alteration, whereas catheterization findings were consistent with a high cardiac output state. Short tricuspid deceleration time (DT) had the best predictive value for subsequent cardiac events. Repeat echocardiographic study in 35 asymptomatic patients at 19 +/- 7 months demonstrated deterioration of LV systolic function, chamber enlargement, and shortening of DT of tricuspid and mitral inflow. CONCLUSIONS: In patients with homozygous beta-thalassemia major without cardiac disease, the pattern of RV filling is abnormally altered, indicating impaired relaxation. In contrast, the LV filling is compatible with increased preload, as in chronic anemia. Short DT of early tricuspid inflow carries important prognostic value. LV remodeling occurs over time along with transition toward a restrictive ventricular filling pattern.

Adolescent↗
PubMed2001

Initial experience with a newer generation coronary stent.

BACKGROUND: Recently, several newer generation stents have become available promising to improve upon the results of coronary angioplasty (PTCA) with its attendant acute and chronic complications. The aim of this study was to prospectively review the results of a preliminary experience with the newer generation R stent in a series of 56 patients. METHODS: This study included 47 men and 9 women, aged 57 +/- 10 years, who presented with stable angina and/or positive exercise testing (n = 12), unstable angina (n = 42), or acute myocardial infarction (n = 2). A consistent approach by a single operator for implantation of the R stent (Orbus Inc., The Netherlands) included stent oversizing (by 0.5 mm) and high pressure (> 12--16 bar) deployment. Dilated vessels comprised the left anterior descending (n = 37) including the diagonal branch in 2 patients, the right coronary artery (n = 17), the left circumflex (n = 13), or a saphenous vein graft (n = 1). The mean left ventricular ejection fraction was 52 +/- 8% and the initial coronary artery stenosis was 85 +/- 8%. Stents were implanted for dissection and/or suboptimal PTCA result or electively. RESULTS: The procedure was successful in all 56 patients (100%). The residual stenosis was < 0--10%. Direct stenting without balloon predilation was performed in 21 patients. Single stents were used in 36 patients and > or = 2 stents in 20 patients. Abciximab (n = 22), eptifibatide (n = 8) or tirofiban (n = 1) was administered in 31 patients (55%). A stent-related complication was noted in one patient (stent misplacement). All patients were discharged alive without infarct or need for surgery. There were no events of subacute stent thrombosis; all patients received combined therapy with aspirin and clopidogrel, the latter for 1 month. In one patient who had received abciximab, severe thrombocytopenia (0 platelet count) was detected at 3 days after discharge but it was fully reversible with no sequelae. Over 5.2 +/- 2.8 (range, 1--11) months, there was one sudden death and two clinical restenoses; no other late complication occurred. CONCLUSION: Initial experience with 73 R stents in 56 patients and a consistent approach by a single operator of stent oversizing and high-pressure deployment resulted in high procedural success (100%), lack of stent thrombosis (0%), and a low stent-related complication rate (1.8%), while the design and profile of the R stent allowed for direct stenting in 37.5% of patients. One should be vigilant for the sporadic occurrence of severe thrombocytopenia with use of IIb/IIIa inhibitors.

Adult↗
PubMed1997

Relationship between left ventricular hypertrophy and plasma renin activity in chronic hemodialysis patients.

Left ventricular hypertrophy (LVH) is very common in uremic patients. It was shown previously that hemodialysis patients are chronically exposed to the extremes of plasma renin activity due to differences in the original renal disease. Because nonhemodynamic factors seem to play a fundamental role in the development of LVH, the present study was undertaken to investigate the relationship between the predialysis renin level and the echocardiographically determined cardiac structure in stable hemodialysis patients, matched for other parameters known to participate in the development of LVH, such as age; gender; body mass index; interdialytic weight gain; heart rate; systolic, diastolic, and mean arterial BP; hematologic and biochemical profile; vascular access; adequacy of dialysis; nutritional status; and period of follow-up. Thirty-three such patients were stratified in three groups according to predialysis renin levels: group A (n = 11), with renin levels < or = 1 ng.ml-1.h-1; group B (n = 9), with renin levels between 1 and 4 ng.ml-1.h-1; and group C (n = 13), with renin levels > or = 4 ng.ml-1.h-1. LVH with disproportionate septal thickening was directly related to the degree of renin-angiotensin system activation, and values for interventricular septum thickness, posterior wall thickness, interventricular septum thickness/posterior wall thickness ratio, left ventricular mass, and left ventricular mass index were all significantly correlated with predialysis renin levels. Because angiotensin II promotes growth in both fibroblasts and cardiac myocytes, these relationships suggest that elevated renin levels may be causally associated with the development of LVH in chronic hemodialysis patients.

Analysis of Variance↗
PubMed1996

Repolarization abnormalities with prolonged hyperventilation in apparently healthy subjects: incidence, mechanisms and affecting factors.

Brief hyperventilation is occasionally accompanied by repolarization abnormalities in subjects without apparent heart disease. However, the effect of prolonged hyperventilation on repolarization abnormalities is not clearly defined. We analysed the repolarization abnormalities induced by prolonged hyperventilation, correlated with hyperventilation induced haemodynamic changes and exercise test results and assessed the effect on them of age, gender, smoking and hypertension. Prolonged hyperventilation (overbreathing at least 30 respirations/min for 5 min and 10 min recovery) was performed in 474 healthy volunteers (269 men, 205 women) 42.6 +/- 13.5 years old. The electrocardiogram was analysed for transient ST depression or T-wave inversion. Repolarization abnormalities were observed in 72 subjects, 47 men (17.5%) and 25 women (12.2%). Age, gender, smoking and hypertension did not influence the overall incidence of repolarization abnormalities. ST depression was more frequently observed in women (4.4 vs 0.7%, P < 0.01), while T wave inversion from negative to positive was more frequent in men (8.9 vs 2.4%, P < 0.006). All subjects with ST depression were non-smokers (4.1% of the non-smokers, P < 0.003 compared to smokers). Repolarization abnormalities occurred usually (80.5%), but not exclusively, within the first hyperventilation minute. Subjects with repolarization abnormalities developed higher heart rate change with hyperventilation than those without repolarization abnormalities (29.2 +/- 13.1 vs 24.2 +/- 12.7, P < 0.002). A positive exercise test was observed in 45.4% of subjects with hyperventilation induced ST depression but only in 13.1% of subjects with T-wave changes, P < 0.02. Repolarization abnormalities are not uncommon during prolonged hyperventilation. Hear rate change affects the occurrence of repolarization abnormalities, while gender and smoking influence the type of repolarization abnormalities. ST depression but not T-wave inversion during hyperventilation is associated with a positive exercise test. Increased understanding about hyperventilation-induced repolarization abnormalities could affect use of the method in the clinic, either as a provocation test or as a complement to the interpretation of the exercise test.

Adult↗
PubMed1990

Low-dose aspirin versus anticoagulants for prevention of coronary graft occlusion.

The prevention of graft occlusion by aspirin (100 mg/day) or heparin followed by phenprocoumon was investigated in a randomized trial in 235 patients after aortocoronary bypass operation. Aspirin treatment started 24 hours before, and heparin 6 hours and phenprocoumon 2 days after surgery. The results of the vein graft angiography and the clinical outcome 3 months postoperatively did not differ: 22% of 218 vein graft distal anastomoses in the aspirin group and 20% of 272 in the anticoagulant group were occluded. At least 1 occluded distal anastomosis was present in 38% of 74 patients in the aspirin-treated group and in 39% of 86 in the anticoagulant group. Worst-case analysis of all randomized patients showed graft occlusions, cardiovascular complications or lost to follow-up in 42% of 122 aspirin-treated patients compared with 41% of 113 patients treated with anticoagulants. For grafts with endarterectomy the occlusion rate was lower in the aspirin (12% of 49) than in the anticoagulant (22% of 41) group (p less than or equal to 0.05). Increased perioperative blood loss in the aspirin group (1,211 +/- 814 ml in the first 48 hours vs 874 +/- 818 ml in the anticoagulant group [p less than or equal to 0.001]) without a higher reoperation rate indicates effective platelet inhibition with low-dose aspirin. Because occlusion rates were equal but high in these patients with advanced stage of coronary artery disease, a combination of low-dose aspirin and anticoagulation should be investigated to reduce graft occlusion rates further.

Aspirin↗
PubMedDate not supplied

Coronary arteriographic findings in symptomatic and asymptomatic subjects with coronary artery calcification.

The relation of coronary artery calcification with the presence of symptoms of coronary artery disease and its angiographic severity is not clear. We studied 37 apparently healthy, asymptomatic subjects that were found by digital cinefluoroscopy to have coronary calcium and compared to age- and sex-matched group of patients with coronary calcium and symptomatic coronary artery disease. Normal coronary arteries and non-obstructive lesions only were found in 12/37 (32.4%) and 11/37 (29.7%) asymptomatic subjects vs. 1/37 (2.7%) and 2/37 (5.4%) patients; P<0.001 and P<0.012, respectively. Obstructive lesions were more rare in asymptomatic subjects than in patients, 14/37 (37.8%) vs. 34/37 (91.9%) (P<0.0001), as well as total occlusions, 2/37 (5.4%) vs. 10/37 (27%) (P<0.024). Median worst lesion stenosis was 30% in asymptomatic subjects and 95% in patients (P<0.0001). In asymptomatic usual cardiovascular risk subjects, coronary calcium detection by digital cinefluoroscopy is accompanied by a relatively high probability of obstructive disease, although less severe angiographically than in age- and sex-matched catheterized patients with symptomatic coronary artery disease.

Aged↗