Clinical Experiences in Radiofrequency Catheter Ablation / 대한내과학회지

OBJECTIVES: Among the current therapeutic options for paroxysmal supraventricular tachycardias, only surgery and ablative techniques are curative. However, surgery is associated with substantial cost, morbidity, and rarely death. Recently, catheter ablation techniques have been developed to treat paroxysmal supraventricular tachycardias. These techniques are effective and low-risk curative treatment for supraventricular tachycardias. This article shall describe our clinical experiences in radiofrequency catheter ablation for supraventricular tachycardias and review the literature. METHODS: The study population consisted of 154 patients with supraventricular tachycardias from January 1993 to August 1995. Eighty one patients were men and seventy three patients were women, and their mean age was 41.29 +/- 15.41 years. Radio-frequency currents(mean) were applied through a catheter electrode positioned against the mitral or tricuspid annulus or a branch of the coronary sinus or atrioventricular node. RESULTS: Among 154 patients, the mechanisms for paroxysmal supraventricular tachycardias were found to be atrioventricular reentrant tachycardia involving a concealed accessory pathway in 51(33.1%), Wolff-Parkinson-White syndrome in 57(37%), and atrioventricular nodal reentrant tachycardia in 46 (29.9%). Successful outcomes were achieved in 46 of 46 patients(100%) with atrioventricular nodal reentrant tachycardia, 7 of 8 patients(87.5%) with double accessory pathways, 69 of 72 patients(95.8%) with left-sided accessory pathway, and 19 of 28 patients (67.9%) with right-sided accessory pathway. Total 141 of 154 patients(91.6%) with supraventricular had a successful outcome with radio-frequency current application(mean). CONCLUSIONS: Radiofrequency catheter ablation techniques are highly effective in ablating accessory pathways or modifying atrioventricular node, with low morbidity and no mortality.

A Case of Coronary Arteriovenous Fistula Confirmed by Echocardiography

Coronary arteriovenous fistula is relatively rare disease and originates more commonly in the right than in the left cononary artery. We report one case of cononary arteriovrnous fistula which we have experienced recently in 22 years old female, who has complained of dyspnea on exertion and intermittent anterior chest pain radiating to the left shoulder for several years. It was detected by transthoracic and transesophageal echocardiography and confirmed by cardiac catheterization and coronary angiography. In this case, the fistula was originated from the right coronary artery and drained into the posterior wall of the right ventricle, the coronary artery was dilated(diameter=1.5cm) and tortuous and significant shunt was measured(Qp/Qs=2.31). The opening of the fistula draining into right ventricle was obliterated with sutures.

Diastolic Function Evaluation in Systemic Arterial Hypertension : A Color M-mode Doppler and Doppler Echocardiographic Analysis

BACKGROUND: Several recent studies have demonstrated that left ventricular diastolic dysfunction is major cause of congestive heart failure and may precede systolic dysfunction or without left ventricular hypertrophy in most patients with systemic arterial hypertension. The purpose of this study is to evaluate left ventricular diastolic function in patients with systemic arterial hypertension compared with normal control group using color M-mode Doppler and Doppler echocardiographic studies. METHODS: From October 1994 to August 1995. 53 patients(18 men and 35 women, mean age : 56.1±12.6 years) with essential hypertension and 30 subjects age-matched nomal controls(13 men and 17 women, mean age 55.9±12.3 years) were included in this study. We measured the early propagation slope of LV inflow by color M-mode Doppler Echocadiography and the peak velocities of E and A wave, E/A tatio, deceleration time of E wave, isovolumic relaxation time by Doppler echocardiography. We also studied left ventricular diastolic function in patients with hypertension who were divided two group(Group I : hypertension with left ventricular hypertrophy, Group II : hypertension without left vetricular hypertrophy). RESULTS: 1) Early propagation slope of LV inflow was significantly decreased in patients with hypertension compared with normal control group(57.43±17.15m/secs vs 69.87±12.71m/secs, p 0.05), whereas deceleration time of E wave was showed increasing tendency in patients with hypertension empared with normal control group(196.57±37.07m/secs vs 189.33±41.35m/secs, p>0.05). 3) Early propagation slope of LV inflow was not significantly different between Group I and Group II, but showing decreasing tendency in Group I compared with Group II(54.72±14.65m/sec vs 60.16±18.96m/sec, p>0.05). Peak velocity of E wave and peak velocity of A wave and E/A ratio and deceleration time were not significantly different between Group I and Group II but peak velocity of E wave and E/A ratio were showed decreasing tendency in Group I(0.65±0.19m/sec vs 0.73±0.22m/sec, 0.86±040 vs 1.04±0.44, p>0.05), whereas peak velocity of A wave and deceleration time of E wave were showed increasing tendency in Group I(0.80±0.20m/sec vs 0.74±0.18m/sec, 199.38±46.45m/secs vs 196.89±24.76m/secs, p>0.05). Only isovolumic relaxation time was significatly increased in Group I compared with Group II(150.63±44.75m/secs vs 120.34±19.77m/secs, p < 0.05). CONCLUSION: Left ventricular diastolic dysfunction may precrede systolic or without left ventricular hypertrophy in patients with systemic arterial hypertension. An early diagnosis of left ventricular diastolic dysfunction, color M-mode Doppler echocardiography and Doppler echocardiography were useful diagnostic stools.

Preoperative Factors Affecting the Outcome of Mitral Valve Replacement in Patients with Chronic Mitral Regurgitation

BACKGROUND: Mitral regurgitation is a valvular heart disease that produce complex hemodynamic alternations and myocardial dysfunction occurs subclinically, so result in a high incidence of left ventricular dysfunction that might affect postoperative result. In order to assess preoperative factors affecting the outcome of mitral valve replacement in patients with chronic mitral regurgitaion, we evaluated prognostic factors from preoperative clinical, laboratory, and echocardiographic findings in 71 patients with chronic mitral regurgitation who received mitral valve replacement. METHODS: From 1985 to 1994, 71 patients with chronic mitral regurgitation, who received mitral valve replacement, were included in this study. The patients were defined as group I who had improved symptom and / or decreased left ventricular end-diastolic dimension after operation, and group II who had persistent symptom and / or over 60mm of left ventricular end-diastolic dimension after operation. RESULTS: 1) In clinical findings, preoperative systolic blood pressure was higher in Group I patients(p<0.05). 2) Hemoglobin, serum creatinine, and blood urea nitrogen level were not significantly different in both groups. 3) In echocardigraphic findings, left atrial dimension, left ventricular end-systolic / end-diastolic dimension, and left ventricular volume index of Group II were much higher than those of Group I patients(p<0.05). 4) In the discriminant analysis, left ventricular end-diastolic dimension, age, NYHA functional class, and left ventricular mass index were defined as important prognostic factors. CONCLUSION: According to the above results, preoperative age, NYHA functional class are significant prognostic factors in clinical and laboratory findings. And left atrial dimension, left ventricular end-systolic and end-diastolic dimensions, left ventricular volume index, and left ventricular mass index are significant prognostic factors in echocardiographic findings.