Irfan Yaqoob

Immediate effect of percutaneous transvenous mitral commissurotomy on atrial electromechanical delay and P-wave dispersion in patients with severe mitral stenosis.

BACKGROUND Mitral stenosis (MS) is associated with prolonged inter- and intra-atrial electromechanical delays and increased P-wave dispersion, which are markers of atrial fibrillation (AF) risk. This study was conducted to assess the immediate effect of successful percutaneous transvenous mitral commissurotomy (PTMC) on these parameters. METHODS This single center observational study included 25 patients with severe MS (aged 34.1 ± 7.1 years, with mean mitral valve area (MVA) of 0.74 ± 0.13 cm(2)), in sinus rhythm, who underwent successful PTMC at our hospital. P-wave dispersion (PWD) was calculated by subtracting minimum P-wave duration (P min) from maximum P-wave duration (Pmax), measured on a 12-lead surface ECG obtained from each patient in supine position at a paper speed of 50mm/s and 20mm/mV. Inter-atrial (AEMD), left intra-atrial (L-IAEMD), and right intra-atrial (R-IAEMD) electromechanical delays were measured on tissue Doppler imaging. PTMC was performed using the standard Inoue Balloon technique. All these parameters were evaluated and compared before and 24-48 h after PTMC. RESULTS Successful PTMC led to significant reduction in AEMD (p < 0.001), L-IAEMD (p < 0.001), and R-IAEMD (p < 0.001). There were no changes in Pmax, Pmin, and PWD immediately after PTMC. CONCLUSIONS Successful PTMC has a favorable early impact on inter- and intra-atrial electromechanical delays, which are considered as novel parameters of atrial electromechanical remodeling in MS patients. Prospective large-scale studies are required to confirm whether improvement in these markers translates into reduced long-term AF risk.

Profile of arrythmogenic right ventricular cardiomyopathy/dysplasia (ARCV/D) patients presenting with sustained ventricular tachycardia in a tertiary care center

Background: Arrhythmogenic right ventricular cardiomyopathy /dysplasia (ARVC/D) is a genetic form of cardiomyopathy and is one among the most common causes of sudden cardiac death (SCD). The aim of our study was to analyze the clinical profile of (ARVC/D) patients presenting with sustained Ventricular Tachycardia (VT). Methods: This single center cohort study evaluated 107 patients who presented with sustained ventricular tachycardia (VT) in our hospital. After aetiological evaluation of all these patients, 15 patients were found to have ARVC/D as the cause of sustained ventricular tachycardia (VT) as per the Modified Task Force Criteria. The clinical profile of these patients was observed in detail to enhance our knowledge about this entity in our part of the world. Results: Mean age at presentation was 30 years and 12 patients were males. Nine patients were haemodynamically stable at the time of sustained VT and the rest of patients were haemodynamically unstable. Left Bundle Branch Block (LBBB) was the most common ECG morphology present in 11 patients. Antiarrhythmic drugs terminated VT in 7 patients. All the 6 patients presenting in a state of haemodynamic instability received DC cardioversion. Mortality occurred in 2 patients during the hospital stay. Conclusions: ARVC/D presenting with sustained VT is an important manifestation of the disease. Males are more commonly affected than females. Haemodynamic instability at the time of presentation carries a poor prognosis.

Components and determinants of therapeutic delay in patients with acute ST-elevation myocardial infarction: A tertiary care hospital-based study

Background Delayed reperfusion is associated with worse outcomes in ST-segment elevation myocardial infarction (STEMI). This study was conducted to assess the components and determinants of therapeutic delay in STEMI patients of our state. Methods This study included consecutive patients of STEMI admitted to the coronary care units of two tertiary care hospitals in Srinagar, between 2012 and 2015. Various components of treatment delay including the patient’s decision to delay, referral delay, transportation delay, prehospital delay, and door-to-needle time were calculated. Factors associated with delayed treatment and clinico-demographic correlates of late presentation were identified. Results During a period of 3 years, 523 patients (mean age, 57.6 ± 10.5 years) were enrolled in this study. Thrombolysis was administered to 60.2% patients, while 39.8% of patients could not be thrombolysed because of late presentation. The median treatment delay was 250 minutes. Prehospital delay constituted about 83.8% of total treatment delay. Patient’s decision to delay, referral delay, and transport delay constituted 59%, 16%, and 25% of prehospital delay, respectively. Median door-to-needle time was 40 minutes. Residence in rural areas [odds ratio (OR), 2.35; 95% confidence interval (CI), 1.60–3.46], absence of prior coronary artery disease (OR, 1.54; 95% CI, 1.00–2.39), and negative family history of coronary artery disease (OR; 2.76; 95% CI, 1.86–4.10), were identified as independent predictors of delayed presentation (p < 0.001). Interestingly, 44.7% of the patients presented late due to misdiagnosis by local healthcare providers. Conclusion The standard of STEMI management in our state is far from ideal, and calls for a lot of improvement. Major efforts to reduce prehospital and in-hospital treatment delays are urgently needed.

Profile of patients presenting with sustained ventricular tachycardia in a tertiary care center

Background and aim Ventricular tachycardia (VT) represents the most frequent cause of sudden cardiac death. Information on clinical characteristics, acute management and outcome of patients with sustained VT is limited in our part of world. The aim of this study was to analyze the demography, hemodynamics, ECG features, underlying disease, mode of termination and outcome of patients presenting with VT. Methods This single center cohort study represents total of 107 patients of VT enrolled over 45 months. Results Mean age was 45 years and 59 of the patients were males. Thirty three of these patients were hemodynamically unstable (31%) and 74 were stable (69%) Coronary artery disease was the most common etiological factor accounting for 39% of patients followed by non-ischemic cardiomyopathy. Determinants of hemodynamic instability were VT in course of acute myocardial infarction (8 out of fourteen) and polymorphic pattern of VT (13 out of 26). Spontaneous termination of VT occurred in seven patients, antiarrythmic drugs terminated VT in 53 of 67 patients and in remaining 45 patients VT was terminated with direct current (DC) cardioversion. Total of twenty three patients died during the hospital stay. Factors that contributed to mortality were old age, hemodynamic instability and low ejection fraction. Conclusion Ischemic heart disease remains the leading cause of VT. Hemodynamically unstable VT occurs more frequently in acute myocardial infarction and polymorphic VT. Most effective method of VT termination is DC cardioversion. Old age, hemodynamic instability and ejection fraction contribute to overall mortality in VT.

Insertion/deletion polymorphism of ACE gene in females with peripartum cardiomyopathy: A case-control study

Background The role of polymorphism of Angiotensin converting enzyme (ACE) gene and ACE activity in etiopathogenesis, prognosis, and many other clinical parameters in the various form of the cardiovascular disease has been established to some degree of certainty. The pathophysiology of Peripartum cardiomyopathy (PPCM) remains an area of active research. The main aim of our study was to see pattern of ACE- Insertion/Deletion (I/D) allele in PPCM and its implications on left ventricular performance indices. Methods This single-center case-control study included 45 cases and 70 controls. The diagnosis of PPCM was established clinically and echocardiographically. ACE genotyping was done by polymerase chain reaction (PCR) method in all subjects. Results The II, ID, and DD genotype was present in 16, 18 and 11 of subjects with PPCM and 48, 19 and 3 of controls respectively. The odds ratio for ACE-II genotype in cases vs. controls was 0.253 (95% CI = 0.114–0.558; p = 0.007), for that of II genotype was 1.93 (95% CI = 0.86–4.3; p = 0.107) and for DD genotype was 7.225 (95% CI; 1.88–27.6; p = 0.0039). Overall frequency of D allele in cases was significantly higher than controls (odds = 4.25; 95% CI = 2.01–6.7; p = 0.0001). Moreover, ejection fraction, left ventricular volume and linear dimensions were worse in patients with DD genotype. Conclusion ACE DD genotype and overall frequency of D allele is significantly higher in patients with PPCM. Also, the presence of DD genotype is associated with worse systolic performance indices measured echocardiographically.

Prevalence and characterization of coronary artery disease in patients with symptomatic bradyarrhythmias requiring pacemaker implantation

Background This study was conducted to assess the prevalence and characterization of CAD in high risk patients requiring pacemaker implantation for symptomatic bradyarrhythmias. Methods This study included 100 patients with symptomatic sinus node dysfunction or atrioventricular block, who were at high risk of CAD or had previously documented atherosclerotic vascular disease (ASCVD). Coronary angiography was performed before pacemaker implantation. CAD was defined as the presence of any degree of narrowing in at least one major coronary artery or its first order branch. Obstructive CAD was defined as ≥50% diameter stenosis. CAD was categorized as single vessel disease (SVD), double vessel disease (DVD), or triple vessel disease (TVD); and obstructive CAD in the arteries supplying the conduction system was sub-classified according to Mosseris classification. Results Out of 100 patients (mean age 64.6 ± 10.7 years), 45 (45%) had CAD. 29% patients had obstructive CAD while 16% had non-obstructive CAD. 53.3% patients had SVD, 15.6% had DVD and 31.1% had TVD. Among patients with obstructive CAD; Type I, II, III and IV coronary anatomies were present in 6.9%, 34.5%, 10.3% and 48.3% patients respectively. Presence of CAD significantly correlated with dyslipidemia (p = 0.047), history of smoking (p = 0.025), and family history of CAD (p = 0.002). Conclusion Angiographic CAD is observed in a substantial proportion of patients with symptomatic bradyarrhythmias and risk factors for CAD. It could be argued that such patients should undergo a coronary work-up before pacemaker implantation. Treatment of concomitant CAD is likely to improve the long term prognosis of these patients.

Genetic Determinants of CYP2C19 Gene *2 and *3 Loss of Function Allelesand Response to Anti Platelet Therapy (Clopidogrel) and CardiovascularEvents. (A Study in Kashmir, North India)

Background: Studies have demonstrated that the mutant *2 and*3 allele of the CYP2C19 loss-of-function polymorphism is associated with diminished metabolization of clopidogrel and an attenuated platelet response to clopidogrel treatment. Since no such study has been conducted in this region, we examined CYP2C19 polymorphism in Acute Coronary Syndrome (ACS) patients on clopidogrel treatment, and its effect on the cardiovascular outcomes. Material and Methods: A total of 100 samples of ACS were included in this study and genotyping of CYP2C19 *2 and *3 gene polymorphisms was performed by a Polymerase chain reaction-Restriction fragment length polymorphism (PCR-RFLP). Results: The distribution of CYP2C19*2 allele wild *1/*1, Heterozygous *1/*2 and homozygous mutant *2/*2 genotypes was 56%, 34% and 10% respectively while for CYP2C19*3 wild*1/*1 and heterozygous *1/*3 genotypes was 84% and 16% respectively. The frequency of compound heterozygotes (*2/*3) was found in 9% (9 of 100 patients). CYP2C19 *1/*2 allele was found in 03 of 34 (8.8%) patients who had CV events followed by 2 of 10 (20%) patients with mutant genotype CYP2C19*2 (*2/*2) on follow up. In the CYP2C19*3, 31.2% having heterozygous genotype (*1/*3) had CV events as compared to 11.9% with *1/*1 (31% v/s 11.9% p> 0 .05). In the poor-metabolizer group (*2/*2 or *2/*3), 20.1% of patients had CV events on follow up compared to 15.6% in the extensive metabolizer group (*1/*1), whereas in the intermediate group only 10% of patients had CV events (p>0.05). Conclusion: We conclude that patients carrying CYP2C19 loss-of-function alleles had a higher rate of subsequent cardiovascular events than as against those with normal allele. Lack of significant events even in presence of variant alleles justifies us to some extent to continue clopidogrel in our patients