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Atul Verma

Publications and source records attributed to Atul Verma.

31 records · Page 2Linked to original sources
PubMed2004

Importance of ablating all potential right atrial flutter circuits in postcardiac surgery patients.

OBJECTIVES: In patients with atrial flutter (AFL) and postoperative right atrial incisional scars, we sought to assess if the use of additional ablative lesions that targeted all potential re-entrant circuits, regardless of the presenting type of flutter, would prevent long-term recurrence. BACKGROUND: Patients with AFL and incisional scars have a complex atrial substrate that may promote multiple mechanisms of intra-atrial re-entry. METHODS: Twenty-nine patients with single right atrial incisional scars undergoing ablation for scar-dependent (n = 15) and cavotricuspid isthmus (CTI)-dependent (n = 14) flutter were studied. RESULTS: In the scar-dependent group, 9 of 15 (60%) patients had inducible or spontaneous CTI-dependent flutter immediately after ablation. In the group with CTI flutter, 7 of 14 (50%) patients had scar-related flutter immediately after ablation. If a second type of flutter was found during the initial ablation, a second ablation was performed either along the isthmus (scar-dependent group) or from the scar to another anatomic boundary (isthmus-dependent group). Patients were followed for 24 +/- 5 months and 18 +/- 6 months in the scar- and CTI-dependent groups, respectively. In the scar-dependent group, five of six (83%) who underwent only a single flutter line had recurrence at 3 +/- 1 months. In the isthmus-dependent group, three of seven (42%) patients who had only one flutter line performed had recurrence at 5 +/- 3 months. There was no flutter recurrence in patients who initially received two different flutter lines or in patients who subsequently underwent a second flutter line at follow-up. CONCLUSIONS: In patients with postoperative right atrial incisional scar and flutter, multiple ablation lines that target both scar-related and classic isthmuses appear necessary to prevent long-term recurrence.

Atrial Flutter↗
PubMed2004

Left septal atrial flutter: electrophysiology, anatomy, and results of ablation.

BACKGROUND: We describe the clinical and electrophysiological characteristics of a novel macroreentrant form of left atrial flutter circuit. METHODS AND RESULTS: A total of 11 patients were included in the study. The mean tachycardia cycle length was 278+/-41 ms. Nine of the 11 patients were treated with antiarrhythmic drugs at the time of the study for concomitant atrial fibrillation. With the use of entrainment pacing and either the CARTO Biosense mapping system (9 patients) or conventional mapping (2 patients), the flutter circuit was found to rotate around the left septum primum with a critical isthmus located between the pulmonary veins posteriorly and/or mitral annulus anteriorly and the septum primum. In 5 patients, radiofrequency ablation was performed from the septum primum to the right inferior pulmonary vein (group 1), and in 6 patients, a lesion was made from the septum primum to the mitral annulus (group 2). After a follow-up of 13+/-6 months, 2 patients in group 1 and all patients in group 2 remained in sinus rhythm without recurrence. CONCLUSIONS: Slowing of electric conduction in the left atrial septum due to antiarrhythmic drugs and/or atrial myopathy seems to promote left septal atrial flutter. Radiofrequency ablation of this arrhythmia is usually effective and safe. A line of block between the septum primum and the mitral annulus proved to be effective for cure of tachycardia.

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PubMed2004

Mode of initiation and ablation of ventricular fibrillation storms in patients with ischemic cardiomyopathy.

OBJECTIVES: We report on the initiation of ventricular fibrillation (VF) storm in patients with ischemic cardiomyopathy (ICM) and the results of targeted ablation to treat VF storm. BACKGROUND: Monomorphic premature ventricular contractions (PVCs) have been shown to initiate VF in patients without structural heart disease. METHODS: A total of 29 patients with ICM and documented VF initiation were identified. In 21 patients, VF storm was controlled with antiarrhythmic drugs and/or treatment of heart failure. Eight patients with VF (mean 52 +/- 25 episodes) refractory to medical management required ablation. All patients underwent three-dimensional electroanatomical mapping using CARTO (Biosense-Webster Inc., Diamond Bar, California), and PVCs were mapped when present. Scarred areas were identified using voltage mapping. RESULTS: Monomorphic PVCs initiated VF in all 29 identified patients. Five of eight patients requiring ablation had frequent PVCs that allowed PVC mapping. The earliest activation site was consistently located in the scar border zone. The PVCs were always preceded by a Purkinje-like potential (PLP). Ablation was successfully performed at these sites. In three patients, infrequent PVCs prevented mapping, but PLPs were recorded around the scar border. Ablation targeting these potentials along the scar border was successfully performed. During follow-up (10 +/- 6 months), one patient had a single VF episode and another developed sustained, monomorphic ventricular tachycardia. There was no recurrence of VF storm. CONCLUSIONS: Ventricular fibrillation in ICM is triggered by monomorphic PVCs originating from the scar border zone with preceding PLPs; targeting these PVCs may prevent VF recurrence. In the absence of PVCs, both substrate mapping and ablation appear to be equally effective.

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PubMed2004

Pulmonary vein isolation for the treatment of atrial fibrillation in patients with impaired systolic function.

OBJECTIVES: We aimed to determine the safety and efficacy of pulmonary vein isolation (PVI) in atrial fibrillation (AF) patients with impaired left ventricular (LV) systolic function. BACKGROUND: To date, PVI has been performed primarily in patients with normal LV function. Yet, many AF patients have impaired LV systolic function. The outcomes of PVI in patients with impaired LV systolic function are unknown. METHODS: We included 377 consecutive patients undergoing PVI between December 2000 and January 2003. Ninety-four patients had impaired LV function (ejection fraction [EF] <40%), and they comprised the study group. The control group was the remaining 283 patients who had a normal EF. End points included AF recurrence and changes in EF and quality of life (QoL). RESULTS: Mean EF was 36% in our study group, compared with 54% in controls. After initial PVI, 73% of patients with impaired EF and 87% of patients with normal EF were free of AF recurrence at 14 +/- 6 months (p = 0.03). In the study group, there was a nonsignificant increase in EF of 4.6% and significant improvement in QoL. Complication rates were low and included a 1% risk of pulmonary vein stenosis. CONCLUSIONS: Although the AF recurrence rate after initial PVI in impaired EF patients was higher than in normal EF subjects, nearly three-fourths of patients with impaired EF remained AF-free. Although our sample size was nonrandomized, our results suggest PVI may be a feasible therapeutic option in AF patients with impaired EF. Randomized studies with more patients and longer follow-up are warranted.

Atrial Fibrillation↗
PubMed2004

Impact of coronary sinus lead position on biventricular pacing: mortality and echocardiographic evaluation during long-term follow-up.

INTRODUCTION: Biventricular pacing is an established treatment for congestive heart failure. Whether the anatomic location of the coronary sinus (CS) lead affects outcomes is unknown. The aim of this study was to evaluate the clinical response and mortality in patients who had transvenous CS leads placed in different anatomic branches for biventricular pacing. METHODS AND RESULTS: We evaluated 233 consecutive patients with New York Heart Association (NYHA) class III-IV heart failure and ejection fraction <35% who had successful placement of a transvenous left ventricular lead through a CS venous branch. Patients were divided into two groups based on anatomic lead position. Group 1 (n = 66) included leads in the anterior and anterolateral branches. Group 2 (n = 167) included leads in the lateral and posterolateral branches. Postimplant, functional capacity improved from an average 3.1 to 2.7 in group 1 (P = 0.001) and from 3.1 to 2.3 in group 2 (P = 0.001). Left ventricular ejection fraction (LVEF) measured by transthoracic echocardiography did not improve significantly in group 1 (pre-LVEF 18%, post-LVEF 20%; P = NS) but increased significantly from 19% to 27% in group 2 (P = 0.008). Despite the difference in ejection fraction response, the mortality in the two groups after a mean follow-up of 546 days was similar (13.6% group 1 vs 17.9% group 2). CONCLUSION: Placement of the CS lead in the lateral and posterolateral branches is associated with significant improvement in functional capacity and greater improvement in left ventricular function compared with the anterior CS location. This improvement does not appear to influence mortality.

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PubMed2004

Prevalence, predictors, and mortality significance of the causative arrhythmia in patients with electrical storm.

INTRODUCTION: Electrical storm (ES) is characterized by either refractory ventricular tachycardia (VT) or ventricular fibrillation (VF). However, little is known about the prevalence, predictors, and mortality implications of the causative arrhythmia in ES. We sought to assess the prevalence, predictors, and survival significance of VT and VF as the causative arrhythmia of ES in implantable cardioverter defibrillator (ICD) patients. METHODS AND RESULTS: Consecutive patients from January 2000 to December 2002 who presented to the ICD clinic with > or = 2 separate ventricular arrhythmic episodes requiring shock within 24 hours were included in the study. ICD interrogation confirmed the number of shocks and provided electrograms for interpretation of the causative arrhythmia. Patients were grouped as VF or VT according to the causative arrhythmia. Their prevalence, predictors, and mortality rates were compared. Of 2,028 patients assessed in the ICD clinic, 208 (10%) presented with ES. VF was the cause of ES in 99 of 208 patients, for an overall prevalence of 48%. Original ICD indication, coronary artery disease, and amiodarone therapy were predictive for the causative arrhythmia. There was no mortality difference between the VT and VF groups; however, both groups had significantly increased mortality compared to a control ICD population without ES. CONCLUSION: VF is the causative arrhythmia for a sizable proportion of patients with ES. The initial ICD indication, coronary artery disease, and amiodarone therapy are predictors of the causative arrhythmias in ES. There does not appear to be any mortality difference between ES patients with VT and VF, but mortality is increased in patients with ES versus control ICD patients without ES.

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PubMed2004

Pulmonary vein antrum isolation: intracardiac echocardiography-guided technique.

Several techniques are used for AF ablation, but no general consensus exists as to which technique is the most effective. At our center, we have developed a technique for isolating the pulmonary veins (PVs) at their antrum. The technique is guided by intracardiac echocardiography (ICE) and mapping with a circular (Lasso) catheter. Our technique was developed based on four crucial principles: 1. Precisely identifying the true border of the PV antrum. 2. Electrically isolating all of the PVs at the level of the antrum. 3. Avoiding risk of PV stenosis by ablating outside of the antrum. 4. Minimizing risk of other complications, such as perforation and stroke, by direct visualization during transseptal access and radiofrequency (RF) ablation.

Atrial Fibrillation↗
PubMedDate not supplied

Coronary calcium and coronary artery disease: an Indian perspective.

BACKGROUND: Coronary artery calcification is a part of the development of atherosclerosis. It occurs exclusively in atherosclerotic arteries and can be used as a noninvasive marker of coronary atherosclerosis. As there is no large-scale study on coronary calcium score reported in the Indian population till date, this study was undertaken for calculating the score in Indians at intermediate-to-high risk of coronary artery disease, and to correlate it with angiographically proven coronary artery disease. METHODS AND RESULTS: A total of 388 consecutive patients who underwent coronary calcium scoring and coronary angiography were included in the study. Calcium scoring was performed based on a modification of the Agatston Score using a high-speed computed tomography scanner (GE CT/i scanner). Coronary calcium scores were correlated with the presence or absence of significant coronary artery disease (defined as > or = 70% stenosis of at least one major epicardial coronary artery) on angiography. Out of 388 patients who underwent coronary angiography, 298 were found to have significant coronary artery disease. Mean coronary calcium score was significantly higher in patients with angiographically proven coronary artery disease (226.7+/-65.2) as compared to those who had normal angiograms (20.29+/-56.7; p value<0.0001). All the 72 patients who had a score > 400 had an abnormal angiogram (sensitivity 23.1%, specificity 100%, positive predictive value 100%, and negative predictive value 24.1%). On the other hand, among the patients who had a score > 0, 298 were found to have abnormal angiograms, while 16 had normal angiograms (sensitivity 95.5%, specificity 78.9%, positive predictive value 94.9%, and negative predictive value 81.1%). CONCLUSIONS: Detection of coronary calcium score by a helical computed tomography scanner is a useful tool for predicting the presence of significant coronary artery disease in intermediate-to-high risk patients. An absolute score of 0 has a high negative predictive value for the presence of coronary artery disease, and may obviate the need to perform coronary angiogram in intermediate-risk patients. On the other extreme, score > 400 is highly predictive of the presence of coronary artery disease, and virtually confirms the presence of significant coronary artery disease in intermediate-to-high risk patients.

Age Distribution↗