Influence of Intrinsic Myocardial Conduction on Paced QRS Morphology During Cardiac Resynchronization Therapy Follow up

We report two cases of patients of cardiac resynchronization therapy (CRT) whose ECGs, during follow up, showed different paced QRS morphology as compared to those of immediate post-device implantation. Parameters of leads, including sensitivity and capture thresholds, were unchanged. There was no lead dislodgement confirmed on fluoroscopy. The ECGs obtained in device off mode showed different intrinsic QRS morphology as compared to those of pre-implant morphology. These changes were attributable to electrolyte imbalance in one patient and progressive intraventricular conduction defect in the other. These cases demonstrate that intrinsic myocardial conduction pattern influences paced QRS morphology. Irreversible change in paced QRS morphology may indicate poor prognosis

Characteristics of the phenotype of mixed cardiomyopathy in patients with implantable cardioverter-defibrillators

OnlinePublBackground or Purpose The prognosis of mixed cardiomyopathy (CMP) in patients with implanted cardioverter-defbrillators (ICDs) has not been investigated. We aim to study the demographic, clinical, device therapies and survival characteristics of mixed CMP in a cohort of patients implanted with a defbrillator. Methods The term mixed CMP was used to categorise patients with impaired left ventricular ejection fraction attributed to documented non-ischemic triggers with concomitant moderate coronary artery disease. This is a single center observational cohort of 526 patients with a mean follow-up of 8.7±3.5 years. Results There were 42.5% patients with ischemic cardiomyopathy (ICM), 26.9% with non-ischemic cardiomyopathy (NICM) and 30.6% with mixed CMP. Mixed CMP, compared to NICM, was associated with higher mean age (69.1 ± 9.6 years), atrial fibrillation (55.3%) and greater incidence of comorbidities. The proportion of patients with mixed CMP receiving device shocks was 23.6%, compared to 18.4% in NICM and 27% in ICM. The VT cycle length recorded in mixed CMP (281.6 ± 43.1 ms) was comparable with ICM (282.5 ± 44 ms; p = 0.9) and lesser than NICM (297.7±48.7 ms; p=0.1). All-cause mortality in mixed CMP (21.1%) was similar to ICM (20.1%; p=0.8) and higher than NICM (15.6%; p = 0.2). The Kaplan–Meier curves revealed hazards of 1.57 (95% CI: 0.91, 2.68) for mixed CMP compared to NICM. Conclusion In a cohort of patients with ICD, the group with mixed CMP represents a phenotype predominantly comprised of the elderly with a higher incidence of comorbidities. Mixed CMP resembles ICM in terms of number of device shocks and VT cycle length. Trends of long-term prognosis of patients with mixed CMP are worse than NICM and similar to ICM.Deep Chandh Raja, Indira Samarawickrema, Sarat Krishna Menon, Rikvin Singh, Abhinav Mehta, Lukah Q. Tuan, Ulhas Pandurangi, Sanjiv Jain, David J. Callans, Francis E. Marchlinski, Walter P. Abhayaratna, Prashanthan Sanders, Rajeev K. Patha

Right atrial appendage tachycardia: A rare cause of tachycardia induced cardiomyopathy in a 4-year-old child

We present a rare case of tachycardiomyopathy in a 4-year-old girl. The child had incessant atrial tachycardia (AT) and refractory heart failure. Right atrial appendage (RAA) was localised as the source of the ectopic tachycardia. The child underwent successful radiofrequency ablation (RFA) using 3-D electroanatomical mapping. Fluoroscopy was used sparingly only to rule out underlying anomalies. The left ventricular functions returned to normal by one month after the procedure. RAA AT is rare in very young children and usually necessitates surgical appendectomies. RFA is a challenge in such age groups and there are very few published literature on RAA AT in very young children. Keywords: Tachycardiomyopathy, Right atrial appendage, Atrial tachycardia, Pediatric arrhythmia, Radiofrequency ablatio

Ebstein′s anomaly with severe aortic stenosis and syncope: Implications in management

Ebstein′s anomaly is a rare congenital heart disease involving the right side of the heart with typical malformations of the tricuspid valve and the right ventricle. Associated left heart anomalies, particularly aortic valve disease, are extremely rare. We report here an unusual case of Ebstein′s anomaly of the tricuspid valve and severe aortic stenosis who presented to us with recurrent syncopal episodes. The patient needed to undergo electrophysiological evaluation before aortic valve replacement to rule out arrhythmic causes of syncope

Characteristics, treatment and one-year outcomes of patients with acute coronary syndrome in a tertiary hospital in India

Background: Coronary artery disease (CAD) is a major cause of death in India. Data on outcome of CAD is scarce in the Indian population. This study determined the characteristics, treatment and one-year outcomes of acute coronary syndrome (ACS) in an Indian Cardiac Centre. Methods: We carried out a cross sectional retrospective analysis of 1468 ACS patients hospitalized between January 2008 and December 2010 and followed up for 1 year in the Institute of Cardiovascular Diseases, Madras Medical Mission, Chennai. Mortality at 1 year, its determinants and 1 year major adverse cardiac events (MACE) were determined. Results: The patients were aged 62.2 ± 11.2 years; males (75.2%) and had ST segment elevation myocardial infarction (STEMI) (33.9%), non ST segment elevation myocardial infarction (44.2%) and unstable angina (21.9%). Key pharmacotherapy included aspirin (98.2%), clopidogrel (95.1%), statins (95.6%), angiotensin converting enzyme inhibitor/angiotensin receptor blocker (50.6%) and beta blocker (83.1%). Angiography rate was 80.6%. In the STEMI group, 53.3% had primary angioplasty, 20.3% were thrombolysed and 16.1% received sole medical therapy. Overall coronary artery bypass graft rate was 12.4%. At one year, all-cause mortality and composite MACE were 2.5% and 9.7%, respectively. MACE included death (2.5%), reinfarction (4.0%), resuscitated cardiac arrest (1.8%), stroke (1.1%) and bleeding (0.4%). Main factors associated with mortality were combined left ventricular systolic and diastolic dysfunction (OR = 20.0, 95% CI = 6.63–69.4) and positive troponin I (OR = 12.56, 95% CI = 1.78–25.23). Troponin I independently predicted mortality. Conclusions: ACS population was older than previously described in India. Evidence-based pharmacotherapy and interventions, and outcomes were comparable to the developed nations

Temporary endoepicardial atrioventricular sequential pacing for complete heart block following complex surgery for congenital heart disease

Complete heart block following intracardiac surgical repair for complex congenital heart disease is not uncommon. In the presence of ventricular dysfunction, ventricular pacing alone may not improve the cardiac output. We report the feasibility and efficacy of endoepicardial atrioventricular sequential pacing in a case of postoperative complete heart block

Risk factors of chronic Kidney disease influencing cardiac calcification

We sought to determine the influence of risk factors of chronic kidney disease (CKD) on cardiac calcification. We studied the correlation between coronary artery calcium score (CACS) and the type and duration of dialysis as well as the presence of diabetes mellitus and hypertension. The relation between calcium score and mortality was also analyzed. Patients with CKD attending the outpatient department or admitted in our hospital were included. They were subjected to high-resolution computerized tomography of the thorax to determine their CACS. Serum levels of intact parathyroid hormone (iPTH), highly sensitive C-reactive protein (hCRP), homocysteine, calcium, phosphorus, and calcium × phosphorus product were measured. Out of the 50 patients studied, 39 were hypertensive (78%), 32 were diabetic (64.4%), 20 were on hemodialysis, and 13 were on continuous ambulatory peritoneal dialysis. The mean CACS was 388.6. Twenty-nine patients had high iPTH levels and 92.9% of them had calcium score >400 (P = 0.013). Twenty-eight patients had high hCRP and 85.7% of these patients had calcium score >400 (P = 0.048). Patients on dialysis for more than two years had higher calcium score >400 (P = 0.035). 43% of diabetics had calcium score >400 (P = 0.008). All the six patients who died had calcium score >400 (P = 0). There was statistically no significant association noted between hypertension, high calcium x phosphorus product, and high homocysteine levels, and high calcium score. Our study suggests that higher values of iPTH, hCRP, and longer duration on dialysis are associated with accelerated cardiac calcification. Calcification scores >400 are associated with increased mortality