Clinical profile and outcomes of semi-permanent pacing in a tertiary care institute in southern India.

BACKGROUND: Semi-permanent pacing (SPP) includes the placement of a permanent lead through the internal jugular vein and connection to a pulse generator on the skin outside the venous access site. AIM: To evaluate the clinical profile and outcomes of semi-permanent pacing in a tertiary care institute in Southern India. METHODS: This is a retrospective observational study. All patients admitted and requiring management with semi-permanent pacing from January 2017 to June 2020 were included. RESULTS: From January 2017 to June 2020, 20 patients underwent semi-permanent pacing (SPP) with a median age of 54 (21-74) years. Males comprised a majority of the patients (55%). Hypertension was noted in 50% of patients and 30% were diabetic. The right internal jugular vein was the most common access in 95% of patients. The most common indication for semi-permanent pacing was pocket site infection in 30% of patients. There were no procedural complications. The median duration on SPP was 7 (5-14) days and the median duration of hospital stay was 13 (8-21) days. Permanent pacemaker implantation was done in 55% of patients. Mortality in our study group was 15% with 10% dying due to cardiogenic shock (post resuscitated cardiac arrest) and 5% dying due to non-cardiac cause (Epidural hematoma). CONCLUSION: In our study, semi-permanent pacing was noted to be a safe procedure and was more commonly indicated in emergent conditions with complete heart block secondary to underlying reversible causes and in the management of pocket site infection.

Study of atrial arrhythmias after surgical or device closure of atrial septal defect.

Background Device closure of atrial septal defect (ASD) has emerged as a treatment modality for the past 3 decades and has changed the natural history of ASD compared to that of surgical closure. Early intervention in ASD retards the geometrical and electrical remodelling of the atrium that contributes to the development of atrial tachyarrhythmias. We studied the incidence of atrial arrhythmias in patients undergoing surgical and device closure of ASD. Methods We did this retrospective observational study at a tertiary referral centre, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala. Patients of all age groups undergoing surgical and device closure of ASD between 1 January 2003 and 31 December 2008 were included to compare the incidence and nature of atrial arrhythmias and also analyse the difference in new-onset atrial arrhythmias between the two arms. Results Of 277 patients, 144 with surgical closure and 133 with device closure were followed up for 10-15 years. A larger number of men underwent surgical closure (41.7%) compared to device closure (25.6%). The mean (SD) follow-up was 12.6 (3.7) years in the surgical closure group and 10.9 (2.6) years in the device closure arm. There were a larger number of patients with atrial tachyarrhythmias in the surgical closure group (6.3%) compared to the device closure group (0.8%) at baseline (p=0.02). A significantly larger number of patients had atrial fibrillation in the surgical closure group (5.6%) compared to the device closure group (0.7%) at baseline (p=0.003). Pulmonary hypertension at baseline was present in 38.9% of patients in the surgical closure group and in 23.3% of patients in the device closure group (p=0.006). New-onset atrial arrhythmias occurred in patients ≥30 years of age (p=0.006) and exclusively in patients with pulmonary hypertension in the surgical group (3.7%) and in the device closure group (6.6%). This was statistically significant in the device closure group (p=0.05) but not in the surgical closure group (p=0.13). The incidence of new-onset arrhythmias was not statistically significant in both groups. Conclusions Atrial arrhythmias were significantly more common in patients who underwent surgical or device closure at ≥ 30 years of age and in patients with pulmonary hypertension. There was no difference in new-onset atrial arrhythmias between the surgical and device closure groups. Our study results suggest that surgical or device closure before 30 years of age and before the development of atrial arrhythmias may be beneficial with respect to the development of atrial arrhythmias.

Transition during radiofrequency ablation of manifest preexcitation. What is the mechanism?

A 45-year-old lady was evaluated for recurrent episodes of palpitation. Her 12­lead electrocardiogram (ECG) showed manifest but incomplete pre-excitation consistent with left sided accessory pathway. There was no structural heart disease by echocardiogram. She underwent an electrophysiology (EP) study after informed consent. A narrow QRS tachycardia consistent with orthodromic AV re-entry got induced. The accessory pathway was mapped to 2 'O clock of the mitral annulus (MA). While radio frequency ablation (RFA) was being performed at that site, an interesting phenomenon was observed (Figs. 1 & 2). What is the mechanism?

Tachycardiomyopathy managed by successful ablation of right ventricular outflow tract premature ventricular complexes.

Tachycardiomyopathy is a common reversible cause of left ventricular dysfunction. Prompt diagnosis and treatment of this condition is essential to ensure a good prognosis for the patient. We report a case of tachycardiomyopathy due to frequent premature ventricular complexes arising from the right ventricular outflow tract midseptum managed with successful ablation.

Tricuspid annular PVCS: Radiofrequency ablation by subtricuspid retrograde catheter approach.

Tricuspid annular PVCs constitute 8% of idiopathic PVCs and 5% of RV PVCs. Although a rare entity to encounter in routine clinical practice, it can be a prime culprit behind major arrhythmic burden in few individuals. Electroanatomic approach with sub tricuspid retrograde catheter technique can target those annular PVCs and decrease the arrhythmia burden to normal or near normal range. Although procedural approach for parahisian PVCs requires a close look to avoid injury to native conduction system, TA PVCs are a real challenge due to inherent catheter instability and contact issue in sub tricuspid retrograde approach.

Narrow QRS tachycardia with extreme rightward axis. What is the mechanism?

A 25 year old lady presented with palpitation to the emergency department. Her pulse rate was 210 beats per minute. She was hemodynamically stable with a blood pressure of 100/60 mm Hg. 12 lead surface electrocardiogram (ECG) was recorded during the presentation (Fig. 1) and rhythm strip (Fig. 2A) during administration of IV adenosine. What is the likely diagnosis?

RBBB tachycardia with north-west axis. What is the mechanism?

RBBB tachycardia with NW axis is considered to be VT unless proved otherwise. However underlying conduction system disease can produce electrocardiographic patterns suggestive of bundle branch block with extreme left axis which can cause difficulty in differentiating VT from SVT as in this case.

An unusual cause of heart failure in a young man.

A 21year old gentleman was admitted with shortness of breath and heart failure. He was noted to have incessant supraventricular tachycardia which was refractory to pharmacological and electrical cardioversion. Electrophysiology study revealed focal atrial tachycardia from an unusual location which was successfully ablated.

Incidentally detected right aortic arch with mirror image branching in a patient with rheumatic calcific mitral valve disease.

An isolated right-sided aortic arch with no congenital heart disease is extremely rare. We report an adult woman with longstanding rheumatic heart disease causing severe calcific mitral stenosis, moderate mitral regurgitation and moderate pulmonary hypertension, for which she underwent mitral valve replacement and tricuspid annuloplasty. On preoperative work-up, she was detected to have a right-sided aortic arch with mirror image branching along with a ductal dimple. However, there were no associated congenital cardiac defects.

Long-term effects of cardiac resynchronization therapy on electrical remodeling in heart failure-A prospective study.

INTRODUCTION: Effects of cardiac resynchronization therapy (CRT) on arrhythmogenicity and sudden death have not been fully ascertained. CRT has been shown to increase transmural dispersion of repolarization (TDR) immediately on implantation, which may favorably remodel on long-term follow-up. However, such a hypothesis has not been prospectively evaluated. METHODS AND RESULTS: We included 35 consecutive patients who underwent CRT implantation between September 2013 and August 2014 (mean age 56.8 ± 11.09 years; 71.43% males). QT and Tpeak-Tend (Tp-e) intervals were measured during endocardial (RVendoP), epicardial (LVepiP), and biventricular pacing (BiVP) at CRT implantation and 1-year follow-up. Compared to RVendoP (130.41 ± 16.75 ms), Tp-e was significantly prolonged during BiVP (142.06 ± 21.98 ms; P < 0.001) and LVepiP (183.45 ± 27.87 ms; P < 0.001) at baseline. There was a significant decrease in Tp-e during BiVP on follow-up (117.93 ± 15.03 ms; P < 0.001). High responders had significantly lower Tp-e at 1 year compared to low responders (113.16 ± 14.3 ms vs 129.59 ± 9.75 ms, P  =  0.004). Tp-e at 1 year had strong negative correlation with reduction in LV end-systolic volumes (r  =  - 0.51; P  =  0.003). Seven patients with sustained ventricular arrhythmias during follow-up had significantly longer baseline Tp-e compared to those without arrhythmias (158.19 ± 17.59 ms vs 139.72 ± 20.94 ms, P  =  0.043). A baseline Tp-e value of ≥ 148 ms had a specificity of 75% and sensitivity of 71% to predict ventricular arrhythmias. CONCLUSIONS: Baseline TDR is greater during BiVP and LV epiP compared with RVendoP in patients with heart failure. However, BiVP causes a significant reduction in TDR reflective of reverse electrical remodeling on long-term follow-up.

Takotsubo syndrome presenting as syncope in a patient with permanent pacemaker.

Takotsubo syndrome is an acute reversible heart failure syndrome triggered by physical or emotional stress, especially in postmenopausal women. Herein, we describe a case of a 31-year-old pacemaker dependent lady who presented with syncope after she was bereaved of her father. Electrocardiogram at admission revealed ventricular paced rhythm at 60/min, prolonged QT interval and frequent runs of torsades de pointes. Transthoracic echocardiogram and left ventriculogram revealed findings typical of Takotsubo syndrome. QT prolongation and torsade de pointes in the context of fixed-rate ventricular pacing imply direct catecholamine toxicity on the ventricular myocardium independent of heart rate.