Radiofrequency catheter ablation of ventricular arrhythmias in patients with hypertrophic cardiomyopathy.

BACKGROUND: Compared to other non-ischemic substrates, there is limited data on the role and outcome of catheter ablation in HCM. The objective of this study is to assess the safety and efficacy of catheter ablation for the treatment of VT in patients with HCM. METHODS: Fourteen patients with HCM and drug refractory VT who underwent catheter ablation at a single center were included in this study. The data was evaluated retrospectively. Acute success, procedure-related complications, and long-term outcomes were documented during follow up. RESULTS: Among the 14 patients (mean age 48.2 ± 8.2 years, 85.7% males, mean LVEF 42.6 ± 6.5%), 4 had an apical aneurysm. Eleven patients had evidence of scar-related VT and three patients had a bundle-branch re-entry VT. The most common sites for scar-related VT were the border-zones of the apical aneurysms, basal septum, and LV lateral wall. Patient either underwent an endocardial ablation or a combined endocardial and epicardial ablation. Acute success was achieved in all patients. In 6 patients VT was terminated during ablation. In two patients, non-clinical VTs were inducible at the end of the procedure. No major or minor complications were observed during and after the procedure in all patients. During long-term follow up, elimination of VTs reached 78%. CONCLUSION: Catheter ablation of VT in patients with HCM is safe and successful in eliminating VT. Combining endocardial and epicardial ablation techniques can potentially lead to better outcomes in these patients. Bundle branch re-entry should be considered as a potential mechanism of VT in patients with HCM.

Serum angiotensin converting enzyme, Erythrocyte sedimentation rate and high sensitive-C reactive protein levels in diagnosis of cardiac sarcoidosis- where do we stand?

BACKGROUND: Cardiac sarcoidosis (CS) is increasingly being recognized in the last two decades. The diagnosis of CS depends on clustering of multiple symptoms, investigations and demonstration of a non-caseating granuloma on histopathology. Serum Angiotensin Converting Enzyme (SACE) level, one of the serological markers, is often elevated in systemic sarcoidosis. However, the yield of SACE level among patients with isolated or predominant CS is unclear. We conducted a retrospective study to assess the prevalence of elevated SACE level among patients with proven CS. MATERIALS AND METHODS: From our Granulomatous myocarditis (GM) registry, 45 biopsy proven CS patients were enrolled. INCLUSION CRITERIA: Clinical diagnosis of CS [HRS definition + Lymph Node biopsy/Endomyocardial biopsy (non-caseating granuloma)]. Exclusion criteria - Other causes of GM like cardiac tuberculosis (TB culture/AFB smear -positive) and patients taking medications affecting SACE level. RESULTS: Among 143 GM cases, 45 CS were analyzed. Mean age:42 ± 11 years (Range 22-63 years, 19 females). With our laboratory reference of SACE (Normal range: 20-70 U/L), 3 out of 45 (6.7%) patients of CS had elevated SACE. In a comparative analysis we found, Erythrocyte Sedimentation Rate (ESR) and High sensitive-C Reactive Protein (Hs-CRP) are much more sensitive, although not specific for CS. Patients with pulmonary involvement more often had elevated SACE level. CONCLUSION: Serum ACE is elevated only in approximately 6.7% of patients with biopsy proven CS. Hence, it is insensitive serological tool for diagnosis of CS even in the active phase of the disease. In contrast, ESR and Hs-CRP emerges to be more sensitive markers of active CS.

Idiopathic right ventricular tract outflow tachycardia induced by high-frequency stimulation.

Ventricular tachycardia arising from the right ventricular outflow tract is one of the common forms of idiopathic ventricular tachycardia. One of the major challenges in mapping and ablation of idiopathic right ventricular outflow tract ventricular tachycardia is noninducibility. Direct stimulation of sympathetic nerves innervating the right ventricular outflow may provide an alternative approach to induce arrhythmia. We report a case of idiopathic right ventricular outflow tract tachycardia in whom tachycardia was noninducible by aggressive conventional stimulation protocols, which was induced by high-frequency stimulation of proximal pulmonary artery and was successfully ablated.

Focal para-hisian atrial tachycardia with dual exits.

Focal atrial tachycardias (AT) in the right atrium (RA) tend to cluster around the crista terminalis, coronary sinus (CS) region, tricuspid annulus, and para-hisian region. In most cases, the AT focus can be identified by careful activation mapping, and completely eliminated by radiofrequency (RF) catheter ablation. However, RF ablation near the His bundle (HB) carries a risk of inadvertent damage to the atrioventricular (AV) conduction system. Here we describe a patient with an AT originating in the vicinity of the AV node, which was successfully ablated earlier from non-coronary aortic cusp (NCC), and recurred with an exit from para-hisian location. Respiratory excursions of the catheter were associated with migration to the area of HIs. This was successfully ablated during controlled apnoea, using 3D electroanatomic mapping.

Renal sympathetic denervation for treatment of resistant hypertension - indigenous technique.

BACKGROUND: The endovascular approach of ablation of renal sympathetic nerves is found to be effective in the treatment of uncontrolled hypertension. We report here our experience with the procedure in eight patients with drug resistant hypertension. METHODS: We included patients in whom the blood pressure remained above 150/90 mmHg despite being on minimum three antihypertensive drugs. Radiofrequency ablation of the sympathetic nerves of both the renal arteries was done using conventional ablation catheters. The patients were followed at 1-month, 3 months and 6 months post procedure and blood pressure recorded. RESULTS: All patients underwent successful renal sympathetic denervation. The mean blood pressure of the patients was 181/102.5 mmHg before the procedure and the average requirement of antihypertensive drugs per day was 4. A significant reduction in both systolic and diastolic blood pressure was observed post procedure which sustained over the follow up period of six months. The mean blood pressure observed at 1-month, 3 and 6 months were 137.5/80 mmHg, 136/81 mmHg and 137.5/81 mmHg, respectively. The average requirement of the number of antihypertensives also was reduced to 2.5 at the end of 6 months. There were no procedural complications. CONCLUSION: Catheter based renal denervation causes substantial and sustained blood pressure reduction without serious adverse events in patients with resistant hypertension.

Stroke prevention in atrial fibrillation--current standard of care and significant unmet medical need.

The estimated prevalence of atrial fibrillation (AF) in Europe is 4.5 million and in America is 5.1 million. Arterial thromboembolism, stroke, and heart failure are the some of the most serious complications of AF. There is a fivefold increase in the risk of stroke and the risk of death doubles among patients with AF when compared with the control population. AF-related strokes are more disabling and fatal. The ESC 2010 guidelines and the 2011 ACCF/AHA/HRS update on the management of patients with AF recommend use of adjusted dose warfarin for all patients with a CHA2DS2-VASc score > or = 1. Though an effective drug, warfarin remains underused due to the several limitations associated with its use. It is limited by a slow onset and offset of action, unpredictable pharmacokinetics, several drug-drug and drug-food interactions and need for regular INR monitoring and dosage adjustments. Newer anticoagulants developed as an alternative to warfarin have better pharmacological and safety profiles and promises effective stroke prevention in AF.

Renal sympathetic denervation for resistant , hypertension--a novel treatment strategy.

Uncontrolled Hypertension(HTN) accounts for significant morbidity and mortality. Despite newer drugs hypertension remains uncontrolled in approximately a third of the patients. The overall prevalence of hypertension in adults > 20 years was 30% in men and 34% in women in 2002. We report 2 patients with uncontrolled hypertension in whom Renal denervation therapy improved the control of blood pressure

CLInical Profile and Side Effects of chronic use of oral Amiodarone in cardiology outpatients department (CLIPSE-A Study)- A prospective observational study.

Background: Amiodarone belongs to Class-III anti-arrhythmic drugs. It is one of the most effective anti-arrhythmic drugs used to treat or prevent several types of arrhythmias including atrial fibrillation, atrial flutter, ventricular tachycardia, and wide complex tachycardia, but unfortunately carries a high toxicity profile. Also, side effects of amiodarone involving various organs can be life-threatening. Materials & methods: This was an observational study carried out for six months i.e from April to September. The study included patients who are on amiodarone for greater than or equal to six months. The required data was collected in-person from the case sheets, treatment charts, and by interviewing the patients. The data for 67 patients was documented in suitable data collection form for analysis. Results: From our study data, it was noted that amiodarone was used for 3 different indications-atrial fibrillation, atrial flutter, and ventricular tachycardia. Among 67 patients enrolled, 38 had no side-effects. Side-effects data in the rest grouped basing on the organ system affected: 9 patients had renal effects, 6 patients had ophthalmic effects, 4 patients had endocrine effects, and 5 patients had hepatic effects. Conclusion: From our study, it is concluded that amiodarone is a safe and effective anti-arrhythmic drug at lower doses i.e. 200-1100 mg/week. When treated in lower doses of 1400-2800 mg/week, many side effects have been incident. Although these effects are mild and develop only after prolonged usage of the drug, it should be used judiciously.

Identifying high risk patients post myocardial infarction with reduced left ventricular function using loop recorders INSPIRE-ELR clinical study.

AIMS: Sudden cardiac death (SCD) continues to be a devastating complication amongst survivors of myocardial infarction (MI). Mortality is high in the initial months after MI. The aims of the INSPIRE-ELR study were to assess the proportion of patients with significant arrhythmias early after MI and the association with mortality during 12 months of follow-up. METHODS: The study included 249 patients within 14 days after MI with left ventricular ejection fraction (LVEF) ≤35% at discharge in 11 hospitals in India. Patients received a wearable external loop recorder (ELR) 5 ± 3 days after MI to monitor arrhythmias for 7 days. RESULTS: Patients were predominantly male (86%) with a mean age of 56 ± 12 years. In 82%, reperfusion had been done and all received standard of care cardiovascular medications at discharge. LVEF was 32.2 ± 3.9%, measured 5.1 ± 3.0 days after MI. Of the 233 patients who completed monitoring (7.1 ± 1.5 days), 81 (35%) experienced significant arrhythmias, including Ventricular Tachycardia/Fibrillation (VT/VF): 10 (4.3%); frequent Premature Ventricular Contractions (PVCs): 65 (28%); Atrial Fibrillation (AF): 8 (3.4%); chronic atrial flutter: 4 (1.7%); 2nd or 3rd degree Atrioventricular (AV) block: 4 (1.7%); and symptomatic bradycardia: 8 (3.4%). In total, 26 patients died. Mortality was higher in patients with clinically significant arrhythmia (at 12 months: 23.6% vs 4.8% with 19 vs 7 deaths, hazard ratio (HR) = 5.5, 95% confidence interval (CI) 2.3 to 13.0, p < 0.0001). Excluding 7 deaths during ELR monitoring, HR = 4.5, p < 0.001. CONCLUSION: ELR applied in patients with acute MI and LV dysfunction at the time of discharge identifies patients with high mortality risk.

Evaluation of bachmann bundle pacing versus right atrial pacing in prevention of atrial fibrillation after coronary artery bypass surgery.

BACKGROUND: In patients undergoing coronary artery bypass surgery (CABGS), occurrence of atrial fibrillation (AF) is common in the postoperative period and is associated with increased morbidity with longer intensive unit care (ICU) and hospital stay. Prevention with antiarrhythmic drugs is of limited success and associated with significant side effects. Therefore alternative approaches, such as Bachmann Bundle pacing, are required. METHODS AND RESULTS: 154 consecutive patients, mean age 58±8.8 years, including 134 males and 20 females, were randomized to three groups; Group I : No pacing n= 54, Group II : RA pacing n= 52, Group III : Bachmann Bundle pacing n= 48. All the groups were well matched with regard to age, left atrial size, ejection fraction and use of beta blockers. Patients in Groups II and III were continually paced at a rate of 100 beats per minute (bpm) or at 10 bpm more than patients' intrinsic heart rate. All the patients were monitored for 72 hours by telemetry and occurrence of AF was noted. Incidence of AF was 0% (none of 48 patients) in Group III as compared to 16.6% in Group I (9 of 54 patients) (p 0.003) and 12.5% in Group II (5 of 52 patients) (p 0.03). There was a trend towards shorter ICU stay in Group III (3.9 days) as compared to Group II (4.5 days) and Group I (4.1 days). Among the three groups, the reduction in mean P wave duration also was greater in Bachmann bundle paced group. CONCLUSION: In patients undergoing CABGS, Bachmann bundle pacing is superior to right atrial / no pacing in the post operative period for preventing occurrence of AF and reducing ICU stay, commensurate with a reduction in mean P wave duration on surface ECG.

Pre-Treatment Myocardial 18FDG Uptake Predicts Response to Immunosuppression in Patients With Cardiac Sarcoidosis.

OBJECTIVES: This study identified predictors of clinical (CR) and echocardiographic response (ER) following immunosuppressive therapy (IST) in patients with cardiac sarcoidosis (CS). BACKGROUND: IST has been the cornerstone of treatment for patients with CS and active myocardial inflammation. However, there are little data to explain the variable response to IST in CS. METHODS: Data of 96 consecutive patients with CS from the Granulomatous Myocarditis Registry were analyzed. All patients underwent a 18fluorodeoxy glucose positron emission tomography-computed tomography (18FDG-PET-CT) before initiation of IST. Response was assessed after 4 to 6 months of therapy. CR was defined as an improvement in functional class (New York Heart Association functional class ≥I) and freedom from ventricular arrhythmias and heart failure hospitalizations. ER was defined as an improvement in left ventricular ejection fraction (LVEF) ≥10%. ER was assessed only in patients with a LVEF <50%. Complete responders had no residual myocardial FDG uptake and fulfilled both response criteria. Partial responders fulfilled only 1 response criteria or had residual FDG uptake. Nonresponders did not fulfill either CR or ER criteria. The uptake index (UI) was defined as the product of maximum standardized uptake value and the number of LV segments with abnormal uptake on 18FDG-PET-CT. RESULTS: Among 91 patients included in the final analysis, 54.9%, 20.9%, and 24.2% of patients were classified as complete and partial responders and nonresponders, respectively. Cox regression analysis (all responders vs. nonresponders) identified the following as independent predictors of response following immunosuppression: LVEF >40% (hazard ratio: 1.61; 95% confidence interval: 1.06 to 7.69; p = 0.031) and myocardial UI >30 (hazard ratio: 1.28; 95% confidence interval: 1.05 to 6.12; p = 0.010). The final model had a good discriminative power (area under the curve [AUC]: 0.85) and predictive accuracy (sensitivity: 85.5%; specificity: 86.4%). Pre-treatment myocardial UI had a strong positive correlation with change in LVEF following immunosuppression. CONCLUSIONS: Pre-treatment 18FDG myocardial uptake was a predictor of CR and ER response to immunosuppression in patients with CS.

Pitfalls in comparison of coronary artery measurements of Indian population with different geographical area studies.

INTRODUCTION: Coronary artery disease (CAD) is the most common cause of morbidity and mortality especially in the developing countries. Coronary artery measurements (CAM) are the most important factor affecting the procedure and outcome of coronary angioplasty (PCI) as well as coronary by-pass operations (CABG). In this study, we aimed to establish a database for the normal CAM as well as for gender difference among the Indian population using quantitative coronary angiography (QCA) with an objective of assessing normal coronary vessel morphology of patients with normal coronaries. MATERIALS AND METHODS: Four thousand angiograms from patients of Indian origin were studied prospectively after procuring the sanction for the same from the ethical committee of the pre-selected hospitals of four states in India. Informed consents were obtained. Post CABG, post PCI patients and patient being diabetic for ≥5 years were also excluded from the study. RESULTS: Ten segments from right and left coronary arteries were taken for diameter measurements. These coronary diameters were indexed to body surface area (BSA) (mean diameter mm/m2 BSA). Among, 4000 patients, 933(23.3%) [M:F-521:412] had normal coronaries and 3067 (76.7%) were diseased. DISCUSSION AND CONCLUSION: The dimensions of the coronary artery segments of Indians were smaller (in BSA indexed and non-indexed data), compared to studies from other continents which can be due to their smaller BSA.

Patterns of ventricular dyssynchrony in congestive heart failure- comparison with controls and implications for patient selection for cardiac resynchronization therapy.

BACKGROUND: Assessment of ventricular dyssynchrony by Tissue Doppler Imaging (TDI) is being increasingly used in patient selection for Cardiac Resynchronization Therapy (CRT). Regional distribution of dyssynchrony has been sparingly addressed in dyssynchrony studies in heart failure population. METHODS: TDI was used to assess prevalence and regional distribution patterns of ventricular dyssynchrony in heart failure (HF) patients with systolic LVdysfunction (LVEF equal or less than 40%) in sinus rhythm. Inter-ventricular dyssynchrony (IVD) and left ventricular dyssynchrony (LVD) equal or greater than 40 msec were considered significant and LVD equal or greater than 65 m sec indicated severe dyssynchrony. RESULTS: 100 HF patients (Wide QRS, Gp I, N =70 & Normal QRS Gp II, N=30, and 25 normal individuals with complete LBBB (n=14) or RBBB (n=11) underwent TDI. IVD was seen in 35 (35%) patients (74% LV delay & 26% RV delay) and LVD in 68 patients (68%). The relative prevalence of lVD and LVD respectively in Group land Group II HF patients was47% vs. 7% (p < 0.001) and 70% vs. 67%. (p=ns) while LVD in Groups A (LBBB, n=41) & B (RBBB, n=26) was 76% and 58%, p=ns. The prevalence ofsevere LVD was similar in Gp I & II (37% and 57%, p=ns), and in Gp A & B (46% & 26%, p=ns). Regional distribution patterns of LVD in normal individuals with bundle branch block showed septal delay in 20%, a prevalence of similar to heart failure population (23%, Gp I, and 21% Gp II, p=ns). Lateral wall delay was demonstrated only in the HF population seen in 33% of Gp I and 47% of Gp II patients, p=ns. CONCLUSIONS: LVD is distributed amongst HF patients with narrow or wide QRS and with LBBB or RBBB with a similar regional distribution. Dyssynchrony in normal individuals with bundle branch block is in the form of septal delay. These findings may have implications for patient selection for CRT and site of LV pacing.

Ablation of incessant orthodromic reciprocating tachycardia in a child with congenitally corrected transposition of great arteries and ebsteinoid malformation of left atrioventricular valve.

We report about a patient with congenitally corrected transposition of the great arteries and ebsteinoid malformation of left atrioventricular (AV) valve who presented with incessant orthodromic atrioventricular reciprocating tachycardia due to a left posteroseptal accessory pathway. Radiofrequency catheter ablation using trans-septal approach successfully eliminated the posteroseptal pathway across the morphologic tricuspid valve. This report highlights the importance of delineating the anatomy of the interatrial septum in complex congenital heart diseases for performing safe trans-septal puncture during ablation of accessory pathways.

Catheter ablation of fascicular ventricular tachycardia.

Fascicular ventricular tachycardia (VT) is an idiopathic VT with right bundle branch block morphology and left-axis deviation occuring predominantly in young males. Fascicular tachycardia has been classified into three subtypes namely, left posterior fascicular VT, left anterior fascicular VT and upper septal fascicular VT. The mechanism of this tachycardia is believed to be localized reentry close to the fascicle of the left bundle branch. The reentrant circuit is composed of a verapamil sensitive zone, activated antegradely during tachycardia and the fast conduction Purkinje fibers activated retrogradely during tachycardia recorded as the pre Purkinje and the Purkinje potentials respectively. Catheter ablation is the preferred choice of therapy in patients with fascicular VT. Ablation is carried out during tachycardia, using conventional mapping techniques in majority of the patients, while three dimensional mapping and sinus rhythm ablation is reserved for patients with nonmappable tachycardia.

Sildenafil improves survival in idiopathic pulmonary arterial hypertension.

AIMS AND OBJECTIVES: Idiopathic Pulmonary Arterial Hypertension (IPAH) is a serious disorder of unknown etiology with limited therapeutic options. Sildenafil has been shown to decrease symptoms, improve hemodynamics and quality of life. Its impact on survival is uncertain. We studied the efficacy of sildenafil in improving survival in patients with IPAH. METHODS AND RESULTS: Data on survival of patients with IPAH was collected from prospectively maintained registry at our hospital from January 1999 to December 2005. Thirty nine patients who were treated with conventional therapy including digoxin, diuretics, anticoagulants and calcium channel blockers prior to January 2001 served as historical controls (control group). One hundred and thirty nine patients received sildenafil additionally from January 2001 (sildenafil group). All patients in sildenafil group showed improvement in symptoms. Survival of patients in sildenafil group was significantly better compared to historical controls receiving only conventional therapy. It was 89%, 43% and 19% in the control group Vs 93%, 75% and 54% in the sildenafil group at the end of 1, 3 and 5 years respectively (P Value=0.0002). Sildenafil was well tolerated and none of the patients had to discontinue the treatment. CONCLUSION: Sildenafil when added to conventional therapy improves symptoms as well as survival significantly compared to conventional therapy alone. Further randomized controlled trials are needed to evaluate its impact on survival when used either alone or in combination with other drugs.

Under-utilization of pacemaker therapy for sinus node dysfunction - Real world data from South Asia.

OBJECTIVE: Chronic symptomatic sinus node dysfunction (SND), the most common bradyarrhythmia, can be effectively managed by permanent cardiac pacing. Yet the care pathway and barriers to adoption of pacing therapy are not well understood - particularly in low volume implanting countries. The IMPROVE Brady study is a quality improvement initiative being conducted at centers in South Asia, Latin America, and Russia. We assessed the rates of SND diagnosis and pacemaker treatment for SND in the South Asia cohort. METHODS: The prospective study enrolled patients with heart rate of ≤50 beats per minute presenting with symptoms including syncope, dizziness, and/or dyspnea from ten centers in India and Bangladesh. Patients were followed to identify the proportion diagnosed with SND and subsequently treated with pacemaker therapy. RESULTS: A total of 508 patients meeting criteria were enrolled and followed on average for 8.3±8.0months. Patients were on average 58 years of age, 77% were male, and 91% had completed at least primary education. An SND diagnosis was made in 368 (72%) of patients, with the majority (80%) of diagnoses occurring within 1 month of enrollment. Of the patients with an SND diagnosis, 63 (17%) were treated with a pacemaker. Reasons for not receiving treatment were: subject refusal or deferred decision (45%), unaffordability (34%), physician determined - not-indicated (20%), and other (1%). Older age, female gender, history of hypertension, lower resting heart rate, and syncopal or pre-syncopal symptoms were associated with a higher probability of implant. CONCLUSIONS: In a care pathway assessment for the diagnosis and treatment of symptomatic SND in South Asia only 1 in 6 patients received pacemaker indicated therapy, largely due to patient refusal and physician decision. Phase II of the study will be aimed to improve this treatment rate.