Significance of ST-segment Depression during Paroxysmal Supraventricular Tachycardia.

Background: ST-segment depression in ECG is a common finding during paroxysmal supraventricular tachycardia. The exact mechanism and etiology of this ST-segment depression is not always evident. In this study we have tried to evaluate the significance of ST-segment depression during supraventricular tachycardia. Methods: Hospitalized patients for elective electrophysiological study with previous (EPS) history of supraventricular tachycardia with or without ST-segment depression were evaluated clinically, by coronary angiogram and EPS. Data were analyzed by appropriate statistical methods and comparison made between groups with ST-segment depression (Group A) and without ST-segment depression (Group B). Results: Total number of patients was 66. Equal number of patients (33) was in each group. The mean age of patients was 43.8 years. There was female predominance (M:F ratio 2:3). The mean heart rate during supraventricular tachycardia was 161 beats/min. Age, sex, coronary artery disease risk factors and heart rate during an episode of supraventricular tachycardia did not have any significant influence on ST-segment depression. Significant coronary artery disease was found in two patients in Group A and one patient in Group B. Electrophysiological study revealed that Atrio ventricular reentry tachycardia (AVRT) and AV nodal reentry tachycardia (AVNRT) were present in 28 (42.4%) and 38 (57.6%) cases respectively. Patients of group A exhibit AVRT significantly more than patients of group B.The sensitivity of ST-segment depression in correctly diagnosing coronary artery disease (CAD) was 66.7% while the specificity was 50.8%. The sensitivity of ST-segment depression in correctly differentiating AVRT was 83.3% while the specificity was 66.7%. The positive predictive value (PPV) and Negative predictive value (NPV) of the test were 75% and 76.9% respectively. Conclusion: ST-segment depression during episode of supraventricular tachycardia is a poor indicator of coronary artery disease. Presence of ST-segment depression can differentiate AVRT from AVNRT. However, >2 mm ST-segment depression was proved to be an excellent predictor of AVRT.

Differences of hemodynamic changes during supraventricular tachycardias: simulation of AVRT and AVNRT in dogs / 대한내과학회지

BACKGROUND: Tachyarrhythmias have various clinical features according to their tachycardia rates, systolic function of the left ventricle, the origin site and the mechanisms. Atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reentrant tachycardia (AVRT) might cause different hemodynamic changes due to their different mechanisms. METHODS: To evaluate the hemodynamic differences of supraventricular tachycardias, atrial tachycardia (atrial pacing with AOO mode, 180/min, group I), AVRT (VA pacing interval 80 msec with DOO mode, 180/min, group II) and AVNRT (VA pacing interval 0 msec, 25 msec with DOO mode, 180/min, group III) were simulated in eleven dogs. Hemodynamic parameters were systemic arterial pressure including systolic, mean and diastolic arterial pressure (SAP, MAP, DAP respectively), mean pulmonary arterial wedge pressure (MPAWP) and cardiac output (CO). RESULTS: The MAP was highest in group I (87.0+/-20.4 mmHg) and decreased with decreasing VA interval of no significance. The SAP was higher in group II (109.8+/-22.6 mmHg) than in group III (95.3+/-27.1 mmHg) (p<0.05). The level of MPAWP had no significant differences among three groups and showed no peculiar pattern with changes of VA interval. The CO was higher in group I (1.18+/-0.32 L/min) than in other two groups with significant difference (p<0.01) and decreased with shortening of VA interval without significance. CONCLUSION: Above results suggested that the AVRT and AVNRT have different effects on hemodynamic changes, those from different timing of atrial contraction, especially on SAP and CO. So hemodynamic compromise during tachycardia could be more severe in AVNRT than in AVRT inspite of their similar QRS morphology and tachycardia rate.

AVRT characterized by paroxysmal occurrence that slow atrioventricular accessory pathway participatesin / 中国实用内科杂志

Objective To study the electrophysiologic characteristics of atrial-ventricular reentrant tachycardia(AVRT)characterized by paroxysmal occurrence that slow atrioventricular accessory pathway participatesin.Methods Twenty-one cases were chosen from patients receiring radiofrequency ablation therapy in Peking University People's Hospital from July in 1999 to January of 2005.The patients with slow atrioventricular accessory pathways diagnosed correctly were divided into two groups with paroxysmal tachycardia and permanent tachycardia in terms of the occurrent frequence of AVRT.The electrophysiologic features of AVRT of two groups were contrastively analyzed.Results Compared with the group of permanent AVRT,it was found that antidromic refractory period of slow atrioventricular accessory pathways was longer[(359?46)ms vs (318?31)ms,P

Coronary Sinus Morphology in Patients with Supraventricular Tachycardia

BACKGROUND: Coronary sinus catheterization is important in electrophysiological studies. However the mor-phologic feature of the coronary sinus and its significance in patients with supraventricular tachycardia (SVT) have not been determined. During diagnostic electrophysiological studies, coronary sinus catheterization was easier in patients with atrioventricular nodal reentry tachycardia (AVNRT) than in patients with atrioventricular reentry tachycardia (AVRT). Therefore, we studied coronary sinus morphology in patients with SVT and compared AVNRT and AVRT patients. METHODS: The size and shape of the coronary sinus were measured in 13 patients who underwent retrograde coronary sinus venogram during electrophysiologic study between May and June 1996. The diagnosis was 7 cases of AVNRT, 2 of Wolff-Parkinson-White syndrome and 4 of concealed bypass tracts (mean age, 40 years : male vs female, 1 : 1.2). RESULTS: The mean coronary sinus ostial diameter was 10.4+/-2.0 mm:for AVNRT, it was 11.4+/-2.2 mm, and for AVRT it was 9.3+/-1.0 mm in left anterior oblique projection (p=0.031). The mean coronary sinus-to-spine angle was 82.6+/-17.4degrees : AVNRT 95.4+/-24.4degrees and AVRT 67.7+/-15.2degrees in anterior posterior projection (p=0.035). CONCLUSION: The coronary sinus ostial diameter of AVNRT patients was significantly larger than that of AVRT patients. This finding may have important implications for arrythmia pathogenesis in such patients.