RESUMEN
BACKGROUND: The significant potential for perioperative and late cardiovascular complications makes careful preoperative cardiac risk assessment imperative in liver transplantation candidates. OBJECTIVE: To determine the sensitivity and specificity of myocardial perfusion scanning for detection of coronary artery disease (CAD) in liver transplantation candidates. PATIENTS AND METHODS: We prospectively evaluated 93 liver transplantation candidates. Patients with known CAD were excluded. All patients, regardless of symptoms and risk factors, underwent myocardial perfusion scanning and coronary angiography. RESULTS: Results of myocardial perfusion scanning were abnormal in 64 patients (68.8%) and normal in 29 patients (31.2%). Of patients with abnormal scans, only 6 (9.4%) had severe CAD at coronary angiography. None of the 29 patients with normal perfusion scans and the 24 patients with fixed defects had severe CAD; however, 6 of 40 patients (15.0%) with reversible perfusion defects had severe CAD at coronary angiography (P = .005). Alcoholic liver disease, reversible perfusion defects at myocardial perfusion scanning, left ventricular systolic dysfunction, and higher low-density lipoprotein (LDL) cholesterol and triglyceride levels were significantly associated with CAD. Defining reversible perfusion defects as a sign of ischemia, and fixed defects and normal perfusion as nonischemic, myocardial perfusion scanning had 100% sensitivity but 61% specificity for severe CAD. The test's accuracy was low (38%). CONCLUSIONS: The results of reversible perfusion defects on myocardial perfusion scanning were sensitive but not specific for CAD in liver transplantation candidates. The high number of false-positive results decreased the test's accuracy.
Asunto(s)
Enfermedad de la Arteria Coronaria/epidemiología , Trasplante de Hígado/fisiología , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Dipiridamol/farmacología , Prueba de Esfuerzo , Femenino , Furosemida/uso terapéutico , Humanos , Masculino , Cuidados Preoperatorios , Factores de Riesgo , Talio/farmacología , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
OBJECTIVES: Left atrium (LA) plays an important role in left ventricular filling. It is well known that right ventricular apical pacing has unfavorable effects on ventricular systolic and diastolic performance. The aim of this study is to evaluate the LA mechanical functions with 2D echocardiography in patients with a permanent pacemaker after short time ventricular pacing. DESIGN: Echocardiographic examination was performed in 38 patients (mean age 63.0+/- 10.9, 18 female) with dual chamber pacemakers or defibrillators (< 20% ventricular pacing within previous 6 months, all of them on sinus rhythm) before and after 4 hours > 90% ventricular pacing at 70 beats per minute in DDD mode with an optimal AV interval. Left atrial volumes (LAV) including at the time of mitral valve opening (Vmax), at closure (Vmin), and at the onset of atrial systole (Volp) were measured. The passive emptying, conduit, active emptying and total emptying volume, stroke volumes were also calculated. RESULTS: No significant differences were noted at baseline and after pacing for absolute Vmax, Volp, passive emptying, conduit, active emptying, total emptying volumes as well as the volumes indexed to body surface area (p >0.05). CONCLUSIONS: Short - time RV pacing seems to have no acute effects on left atrial mechanical functions.
RESUMEN
BACKGROUND: P-wave duration is defined as the time measured from the onset to the offset of the P-wave in surface electrocardiogram (ECG). Prolonged P wave duration and increased P wave dispersion (PWD) have been reported to carry an increased risk for atrial fibrillation. AIM: Our aim was to evaluate the role of hyperthyroidism on P wave duration and dispersion, to investigate the effect of anti-thyroid therapy on P wave duration and dispersion. MATERIAL AND METHODS: A total of 44 consecutive subjects (22 patients with newly diagnosed overt hyperthyroidism and 22 randomly selected euthyroid healthy subjects) were enrolled in the study. Transthoracic echocardiography, 12 lead surface ECG and thyroid hormone levels were studied at the time of enrollment, in the first and third months of the 6-8 mg/kg/day propylthiouracil therapy. Patients were followed-up for 3 months. RESULTS: Patient and control groups were consisted of age and sex matched subjects. Baseline left atrial diameter was similar between the patient and control groups (3.4+/-0.3 cm and 3.4+/-0.3 cm respectively, p=0.813). The maximum P-wave duration (P maximum) was 113.1+/-6.6 and 105.7+/-4.1 ms in patient and control groups (p=0.001). PWD was 31.5+/-9.5 and 25.2+/-5.9 ms in patient and control groups respectively (p=0.015). At the third month of propylthiouracil treatment P maximum and PWD were decreased in the patient group at statistically significant level and returned back in normal limits (p<0.001 and p=0.001). CONCLUSION: P wave duration and PWD are found prolonged in hyperthyroid patients and propylthiouracil treatment decreased them effectively. This mechanism may establish how the anti-thyroid treatment may prevent the development of atrial fibrillation in hyperthyroid patients.