Changes of Plasma Endothelin-1 Concentration after Percutaneous Mitral Commissurotomy

BACKGROUND: Endothelin, a very potent vasoconstricting substance released from the endothelium, has been known to be elevated in various cardiovascular disorders, however, the sites of endothelin porduction as well as the influence of acute hemodynamic changes upon plasma endothelin-1 concentration remains elucidated. METHODS: In order to evaluate the probable site of endothelin production and relationship between levels of plasma endothelin and hemodynamic variables, six patients with moderate to severe mitral stenosis underwent percutaneous mitral commissurotomy(PMC) were included. Measurement of mean pulmonary arterial pressure, cardiac output as well as plasma endothelin-1 concentration of renal vein, main pulmonary artery, and ascending aorta were performed before and 20 minutes after PMC. RESULTS: After PMC, cardiac output increased significantly, whereas mean pulmonary artery pressure and transvalvular pressure gradient were reduced significantly(both p<0.05). Before PMC, plasma endothelin-1 concentration tended to be higher in renal vein(6.12+/-3.7pg/ml) and pulmonary artery(5.07+/-1.7) than that in aorta(3.05+/-1.2pg/ml). After hemodynamic improvement with PMC, plasma endothelin-1 concentration decreased at all the site, however the change at pulmonary artery was statistically significant. CONCLUSION: These results suggest that endothelin-1 may be produced mainly somewhere in systemic venous circulation such as kidney rather than pulmonary circulation, and plasma endothelin-1 concentration tends to decrease in response to the acute hemodydnamic im provement.

Echocardiographic Characteristics of Normally Functioning CarboMedics and St.Jude Medical Mitral Valve

BACKGROUND: CarboMedics and St.Jude Medical bileaflet valves are in widespread use but few noninvasive studies about the two types of valves were performedd. The aim of this study was to assess the characterisics of the normally functioning CarboMedics and St.Jude Medical prosthesis in the mitral position. METHODS: Patients with normally functioning CarboMedics and St.Jude Medical valve in the mitral position were included. They underwent transthoracic and transesophageal echocardiography 7 to 14days after mitral valve replacement. With the use of color flow Doppler transesophageal echocardiography, we measured the length, width, and area of maximal physiologic regurgitation and by using 2-D transesophageal echocardiography, we measured the opening and closing angles of the bileaflet valves and we tried to elucidate whether spontaneous echo contrast is present in the left atrium. RESULTS: 31 pateints underwent mitral valve replacement with CarboMedics and 10 patients with St.Jude Medical. The length of maximal physiologic regurgitation ranged from 11mm to 44mm in carboMedics mitral valve and from 12mm to 36mm in St.Jude Medical mitral valve. The area ranged from 0.19cm2to 3.48cm2in CarboMedcs and from 0.58cm2to 4.49cm2in CarboMedics and The mean opening and closing angles are 83.2(+/-1.1)degrees, 22.3(+/-1.3)degrees in CarboMedics and 86.5(+/-1.2)degrees 26.2(+/-3.2)degrees in St.Jude Medical. Spontaneous echo contrast was positive in 66% of patients, of whom patioents with atrial fibrillation showed nuch higher revalence of SEC than patients with sinus rhythm. CONCLUSION: These finding valve will give us a reference valvue for the evaluation of prosthetic valve function in mitral position.

Risk Factors of the Atherosclerotic Peripheral Vascular Disease(PVD)

BACKGROUND: The main cause of atherosclerotic peripheral vascular disease is known to be atherosclerotic processing. In patients with atherosclerotic peripheral vascular disease, other atherosclerotic diseases are frequently combined, especially coronary artery disease. There were some suggestions that the risk factors of the atherosclerotic peripheral vascular disease be different from the those of the coronary artery disease. The aim of this study was to evaluate the independent risk factors for the atheroslerotic peripheral vascular disease(PVD) without influence of coronary artery disease(CAD). METHODS: The study population was male patients with atherosclerotic peripheral vascular disease(n=66) documented by peripheral angiogram form February 1991 to Octobor 1993, and during their abmission all patients with suspected atherosclerotic peripheral vascular diaease underwent both peripheral angiogram and coronary angiogram. Careful history taking and physical examination and lipid battery sampling after at least 14 hours of fasting were also performed. RESULTS: 60% of patients with peripheral vascular disease also had coronary artery disease. There was no significant difference in total cholesterol, HDL cholesterol, LDL cholestrerol, triglyceride between patients with peripheral vascular disease and age-matched control. The prevalence of hypertension was higher in patients with peripheral vascular disease but with no statistical significance. Smoking(p<0.0001) and diabetes(p<0.05) were strongly associated with peripheral vascular disease. When patients without coronary artery disease were compared to control from the viewpoint of risk factors again, the results were the same, that is, smoking and diabetes were also associated with periperal vascular diseaes. CONCLUSION: The prevalence of associated coronary artery disease was relatively high in patients with atherosclerotic peripheral vascular disease. And smoking and diabetes seem to be important risk factors of atherosclerotic peripheral vascular disease.

Prevalence of the patent foramen ovale in young patients with ischemic cerebrovascular disease: Transesophageal contrast echocardiographic study

BACKGROUND: A paradoxical embolism through the patent foramen ovale has been suggested as a possible cause of ischemic cerebrovascular disease in young patients without other cardiovascular risk factors, however, the transesophageal contrast echocardiographic examination is proved to be sensitive and accurate to detect the patent foramen ovale in vivo by demonstration a right-to-left shunting of microbubbles at the interatrial septum. METHODS: Transesophageal contrast echocardiographic examinations were performed in 16 young patients(32+/-6 years, 19~39) with ischemic cerebrovascular diseases without other cardiovascular risk factors. Contrast agents were injected twice in each patients, one with Valsalva maneuver and the other with coughing and the presence of the patent foramen ovale was confirmed by demonstrating echogenic contrast crossing the interatrial septum. RESULTS: The patent foramen ovale was demonstrated in five of sixteen patients(31.2%) during transesophageal contrast echocardiographic examination. Although the prevalence of the patent foramen ovale in normal population has not been examined in this study, the prevalence in patient group appears to be significantly higher than that of normal population. CONCLUSIONS: Taken together, a paradoxical embolism through the patent foramen oval appears to be one of the causative factors and a transesophageal contrast echocardiography is recommended especially in young ischemic cerebrovascular disease patients who have normal transesophageal echocardiographic findings and no known risk factors.

A case of AV reentrant tachycardia utilizing a left lateral accessory pathway with long VA conduction time

A patient, 59 years old male, with paroxysmal AV reentrant tachycardia utilizing a concealed left lateral accessory pathway with long VA conduction time is presented. During tachycardia P waves were negative in leads I, aVL, and V6 and positive in leads aVR and V1. The R-P/P-R ratio was 1.6. Radiofrequency catheter ablation was successful to interrupt the VA conduction through the accessory pathway.

Clinical Utility of Transesophageal Echocardiography(TEE) in Prosthetic Valve Dysfunction

BACKGROUND: Better imaging resolution and less flow masking with TEE than with TTE makes it easier to evaluate the prosthetic valve dysfunction. However, direct comparison between two methods to evaluate prosthetic valve dysfunction remains elucidated. METHODS: Both TTE and TEE were performed in 19 patients with suspected prosthetic valve dysfunction who were admitted to Seoul National University Hospital for evaluating porsthetic valve dysfunction from July, 1992 to May, 1993 and those findings were compared with those of cardiac catheterization and angiography, and surgery 19 cases were included in this study. RESULTS: 11 patients with congestive heart failure underwent TTE, TEE and angiography and each finding was compared to one another. We could see that there is good correlation between transesophageal echocardiographic and angiographic grading in the severity of regurgitation but poor correlation between transthoracic echocardiographic and angiographic finding in that of regurgitation. We also could differentiate between central and eccentric leakage with TEE and in 2 cases TEE enabled us to detect a vegetation on prosthetic valve not detected with TTE and in 1 case the cause of cardiac hemolysis could be known with TEE : eccentric leakage in prosthetic mitral valve. Left atrial thrombi were detected with TEE in two patients with recent cerebral infaction history. CONCLUSION: We conclude that TEE is a good method that enables us to diagnosize the prosthetic valve dysfunction and detect the structural abnormalities surrounding prosthetic valve such as paravalvular leakage, vegetation, cardiac hemolysis and Left atrial thrombi not detected easily by TTE.