Presence of Macrovolt T Wave Alternans and Short Coupled PVC Simultaneously in a Patient with Long QT Syndrome

This report presents a patient with macrovolt T wave alternans, PVC with R on T or a long-short sequence followed by torsades de pointes

Change in Atrial Activation Pattern during Ablation of Atrial Flutter

Different types of supraventricular tachycardia have been reported in patients with history of surgical repair of Tetralogy of Fallot. This report presents appearance of focal atrial tachycardia during radiofrequency ablation of the cavotricuspid isthmu

Concealed Malfunction of The Temporary Pacemaker

The 12-lead ECG shows sequential atrial and ventricular pacing (Figure 1A). A tracing, obtained simultaneously during pacemaker interrogation, disclosed pacemaker functioning as VDD mode (Figure 1B). The careful examination of this pacemaker tracing showed that there is a pacing stimulus before each P wave (compatible with DDD mode). This paradox can only be explained by displacement of the temporary pacing lead to right atrium and right atrial stimulation by temporary pacemaker. In this setting, each temporary pacemaker-induced atrial depolarization is tracked by the right atrial lead of the permanent pacemaker as intrinsic P wave. Fluoroscopic study confirmed this explanation (Figure 2). The displaced temporary pacing lead was seen near the lateral right atrial wall. Temporary pacemaker lead had been inserted before replacement of permanent pacemaker

Infra-His Block in a Normal Heart

A 55 year old man with history of palpitation was referred for electrophysiologic study. Baseline ECG, physical examination and transthoracic echocardiographic study were normal. Electrophysiologic study revealed normal AH and HV intervals. Pacing of right atrium with a cycle length of 300 msec showed 2:1 AV block. AH interval was 252 msec and the block was infra-his (Figure 1). With continual of right atrial pacing, one to one AV conduction with increasing AH interval to 282 msec and QRS widening (LBBB pattern) were being observed. HV intervals during 2:1 block and during 1:1 AV conduction were normal. What is the mechanism? Is it an abnormal finding in this patient

Shortening of ventriculoatrial interval after ablation of an accessory pathway

A 21-year old man with history of 8 year palpitation was referred for electrophysiologic study and possible radiofrequency ablation. Physical examination and transthoracic echocardiographic study did not disclose any abnormality. Baseline ECG showed normal sinus rhythm with normal PR and QRS intervals and no evidence of preexcitation. Antiarrhythmic drugs (propranolol and verapamil) were discontinued two days before the procedure. Baseline intervals in sinus rhythm were as follows: sinus cycle length=690 msec, AH=74 msec, HV=37 msec, QRS=90 msec, PR=133 msec. The minimal pacing cycle length maintaining 1:1 antegrade conduction (AVWP) was 320 msec and the minimal pacing cycle length maintaining 1:1 retrograde conduction (VAWP) was 400 msec. Single extrastimulus testing in the right atrium and the right ventricular apex leaded to a sustained narrow complex tachycardia. The arrhythmia was a short PR- long RP tachycardia with following characteristics: cycle length=376 msec, AH=141 msec, HV=42 msec, VA=200 msec, HA (HRA) =236 msec, HA (His) =243 msec and eccentric atrial activation during the arrhythmia (Figure 1). The arrhythmia was easily reproducible with stable hemodynamic

Predictors of local venous complications resulting from electrophysiological procedures

Background: Thromboembolic complications resulting from radiofrequency catheter ablation (RFCA) have an overall incidence of 0.6%. Multiple intracardiac catheters are often necessary for electrophysiological study and RFCA therapy. Therefore, the placement of multiple venous sheaths in one femoral vein is always required for multiple intracardiac catheter insertion. The safety of the placement of multiple separate venous sheaths has been studied previously in a non-randomized study, but the placement of multiple sheaths via one venous line has not been fully studied. Methods and Results: A randomized clinical trial was conducted with a total of 200 patients. We studied the safety of placing multiple sheaths via one venous line, and the effect of heparin on deep vein thrombosis (DVT) and on in situ thrombosis. DVT was not seen in our patients. We observed a significant decrease in the rate of in situ thrombosis in patients who received heparin during the procedure (28% vs 11%, p = 0.04). The type of cannulation changed the in situ thrombosis rate independently of the heparinization protocol. The rate of in situ thrombosis was higher when placing sheaths via one venous line regardless of the heparinization protocol used (16% vs 6%, p = 0.1 for the group on heparin, and 38% vs 18%, p = 0.04 for the other group). In the group cannulated with only one venous line (100 patients), heparinization significantly decreased the rate of in situ thrombosis (16% vs 38%, p = 0.023), but there was an insignificant decrease in the separate cannulation group (6% vs 18%, p = 0.12). Advanced age had no effect on thrombosis. Surprisingly, there was a significantly greater rate of in situ thrombosis (not DVT) among women than among men (26% vs 11%, p = 0.01), regardless of the heparinization protocolor the type of cannulation. Conclusions: Given the local venous complications and DVT after electrophysiological procedures, heparinization is not necessary for right-sided electrophysiological procedures. In situ thrombosis is a minor complication that can be reduced by heparinization in patients undergoing one-line cannulation and in women during longer procedures. (Cardiol J 2012; 19, 1: 15–19

Early Risk stratification for Arrhythmic death in Patients with ST-Elevation Myocardial Infarction

BACKGROUND: Sudden cardiac death is a leading cause of death in patients with ST-elevation myocardial infarction (MI). According to high cost of modern therapeutic modalities it is of paramount importance to define protocols for risk stratification of post-MI patients before considering expensive devices such as implantable cardioverter-defibrillator. METHODS: One hundred and thirty seven patients with acute ST-elevation MI were selected and underwent echocardiographic study, holter monitoring and signal-averaged electrocardiography (SAECG). Then, the patients were followed for 12 ±3 months. RESULTS: During follow-up, 13 deaths (9.5%) occurred; nine cases happened as sudden cardiac death (6.6%). The effect of ejection fraction (EF) less than 40% on occurrence of arrhythmic events was significant (P<0.001). Sensitivity and positive predictive value of EF<40% was 100% and 76.95% respectively. Although with lesser sensitivity and predictive power than EF<40%, abnormal heart rate variability (HRV) and SAECG had also significant effects on occurrence of sudden death (P=0.02 and P=0.003 respectively). Nonsustained ventricular tachycardia was not significantly related to risk of sudden death in this study (P=0.20). CONCLUSION: This study indicated that EF less than 40% is the most powerful predictor of sudden cardiac death in post MI patients. Abnormal HRV and SAECG are also important predictors and can be added to EF for better risk stratification