Amit Noheria

Catheter ablation vs antiarrhythmic drug therapy for atrial fibrillation: a systematic review

BACKGROUNDnCircumferential pulmonary vein ablation (CPVA) has become common therapy for atrial fibrillation (AF), but results of large randomized controlled trials comparing this procedure with antiarrhythmic drug therapy (ADT) have not been published to date. We conducted a systematic literature review to assess whether CPVA is superior to ADT for the management of AF.nnnMETHODSnWe searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials for relevant randomized controlled trials. Data were abstracted to construct a 2 x 2 table for each trial. Recurrence of any atrial tachyarrhythmia (AT) was considered the primary end point of the trials. The estimate and confidence interval for the pooled risk ratio of AT recurrence-free survival in the CPVA group vs the ADT group were obtained using the random-effects model.nnnRESULTSnFour trials qualified for the meta-analysis. In total, 162 of 214 patients (75.7%) in the CPVA group had AT recurrence-free survival vs 41 of 218 patients (18.8%) in the ADT group. The random-effects pooled risk ratio for AT recurrence-free survival was 3.73 (95% confidence interval, 2.47-5.63). In addition, fewer adverse events were reported in the CPVA group compared with that in the ADT group.nnnCONCLUSIONSnWe observed statistically significantly better AT recurrence-free survival with CPVA than with ADT. These results highlight the need for larger trials to determine the appropriate role for CPVA in the management of AF. Ongoing clinical trials may provide further guidance on these treatment options for AF.

Noninvasive Cardiac Radiation for Ablation of Ventricular Tachycardia

BACKGROUND Recent advances have enabled noninvasive mapping of cardiac arrhythmias with electrocardiographic imaging and noninvasive delivery of precise ablative radiation with stereotactic body radiation therapy (SBRT). We combined these techniques to perform catheter‐free, electrophysiology‐guided, noninvasive cardiac radioablation for ventricular tachycardia. METHODS We targeted arrhythmogenic scar regions by combining anatomical imaging with noninvasive electrocardiographic imaging during ventricular tachycardia that was induced by means of an implantable cardioverter–defibrillator (ICD). SBRT simulation, planning, and treatments were performed with the use of standard techniques. Patients were treated with a single fraction of 25 Gy while awake. Efficacy was assessed by counting episodes of ventricular tachycardia, as recorded by ICDs. Safety was assessed by means of serial cardiac and thoracic imaging. RESULTS From April through November 2015, five patients with high‐risk, refractory ventricular tachycardia underwent treatment. The mean noninvasive ablation time was 14 minutes (range, 11 to 18). During the 3 months before treatment, the patients had a combined history of 6577 episodes of ventricular tachycardia. During a 6‐week postablation “blanking period” (when arrhythmias may occur owing to postablation inflammation), there were 680 episodes of ventricular tachycardia. After the 6‐week blanking period, there were 4 episodes of ventricular tachycardia over the next 46 patient‐months, for a reduction from baseline of 99.9%. A reduction in episodes of ventricular tachycardia occurred in all five patients. The mean left ventricular ejection fraction did not decrease with treatment. At 3 months, adjacent lung showed opacities consistent with mild inflammatory changes, which had resolved by 1 year. CONCLUSIONS In five patients with refractory ventricular tachycardia, noninvasive treatment with electrophysiology‐guided cardiac radioablation markedly reduced the burden of ventricular tachycardia. (Funded by Barnes–Jewish Hospital Foundation and others.)

Single-site ventricular pacing via the coronary sinus in patients with tricuspid valve disease

AimsnTo evaluate coronary sinus single-site (CSSS) left ventricular pacing in adult patients with normal left ventricular ejection fraction (LVEF) when traditional right ventricular lead implantation is not feasible or is contraindicated.nnnMethods and resultsnWe performed a retrospective analysis of 23 patients with tricuspid valve surgery/disease who received a CSSS ventricular pacing lead to avoid crossing the tricuspid valve. Two matched control populations were obtained from patients receiving (i) conventional right ventricular single-site (RVSS) leads and (ii) coronary sinus leads for cardiac resynchronization therapy (CSCRT). Main outcomes of interest were lead stability, electrical lead parameters and change in LVEF during long-term follow-up. Successful CSSS pacing was accomplished in all 23 patients without any procedural complications. During the 5.3u2009±u20092.8-year follow-up 22/23 (95.7%) leads were functional with stable pacing and sensing parameters, and 1/23 (4.3%) was extracted for unrelated reasons. Compared to CSSS leads, the lead revision/abandonment was similar with RVSS leads (Hazard ratio (HR) 0.87, 95% confidence interval (CI) 0.03, 22.0), but was higher with CSCRT leads (HR 7.41, 95% CI 1.30, 139.0). There was no difference in change in LVEF between CSSS and RVSS groups (-2.4u2009±u200911.0 vs. 1.5u2009±u200912.8, Pu2009=u20090.76), but LVEF improved in CSCRT group (11.2u2009±u200916.5%, Pu2009=u20090.002). Fluoroscopy times were longer during implantation of CSSS compared to RVSS leads (25.6u2009±u200924.6u2009min vs. 12.3u2009±u200918.6u2009min, Pu2009=u20090.049).nnnConclusionnIn patients with normal LVEF, single-site ventricular pacing via the coronary sinus is a feasible, safe and reliable alternative to right ventricular pacing.

Unusual Atrioventricular Reentry Tachycardia in Congenitally Corrected Transposition of Great Arteries: A Novel Site for Catheter Ablation

A 19-year-old male with congenitally corrected transposition of the great arteries (ccTGA; S, L, L–situs solitus, l-loop, l-transposition)1,2 presented with recurrent frequent palpitations, fatigue, and effort intolerance. Previous history was significant for initial presentation with supraventricular tachycardia (SVT) at the age of 14 years. Transthoracic echocardiography at that time led to diagnosis of ccTGA. He reportedly underwent a posteroseptal accessory pathway ablation, and subsequently a second ablation the same year for recurrent SVT, again targeting a posteroseptal pathway. At the age of 17 years, he had a third procedure and reportedly linear ablation between the right atrioventricular valve (mitral), and inferior vena cava was performed for inducible right atrial flutter. Physical examination was unremarkable except for loud aortic closure on cardiac auscultation. The baseline ECG showed the presence of septal Q waves and the absence of lateral Q waves, findings characteristic of ccTGA (Figure 1A).1 The chest radiograph showed mesocardia without cardiomegaly or pulmonary congestion. Transthoracic echocardiography showed ccTGA, no atrial or ventricular septal defect, no pulmonary stenosis, normally functioning competent atrioventricular valves, and preserved function of both ventricles. Ambulatory monitoring revealed tachycardia, sometimes regular but at other times with an alternating variation in QRS axis and RR interval (Figure 1B). He was brought to the electrophysiology laboratory, and catheters were positioned in standard positions, including high right atrium, His-bundle, subpulmonic ventricle, and coronary sinus (CS). Dissociated signals were noted in the posteroseptal region/CS ostium, presumably related to previous ablations. With premature atrial beats, a distinctly different QRS complex with loss of notching in the inferior leads and a slightly more superior axis was noted. This second more superiorly directed QRS morphology was associated with a shortening in the recorded HV interval. There was no VA conduction. SVT was easily inducible with atrial extrastimuli and …

Acute right ventricular failure and pulseless electrical activity arrest following auto-transfusion of blood

Air embolism is a rare but potentially catastrophic complication of interventional procedures. The occurrence of acute right ventricular dysfunction during intraoperative auto-transfusion of blood, presumably related to pulmonary embolism of agitated air microbubbles and microthrombi, is less commonly recognized. We report a case of auto-transfusion complicated by acute right ventricular failure and pulseless electrical activity arrest. Auto-transfusion of recovered blood is a practical solution to reduce need for post-procedure allogenic transfusions. Although such interventions are frequently performed without complications, they do have inherent risks that should be readily acknowledged. This case clearly describes a severe complication and sequelae of auto-transfusion. <Learning objective: Auto-transfusion of recovered blood is commonly performed in surgical and interventional procedures to reduce the need for allogenic transfusion. Despite this benefit, the risks and complications of auto-transfusion can be severe and must be considered. We report a case of intraprocedural auto-transfusion resulting in introduction of air emboli and subsequent cardiac arrest. Additionally, we provide a brief review of air emboli and underlying pathophysiology that leads to cardiovascular decline.>.

Ablation Approaches for Ventricular Fibrillation

Invasive electrophysiology (EP) mapping and catheter ablation has increasingly become the standard of care for many cardiac arrhythmias like supraventricular tachycardias, atrial fibrillation, premature ventricular complexes (PVC), and monomorphic ventricular tachycardia. In this review, we discuss the recent progress made in the mapping and ablation of ventricular fibrillation (VF). Ventricular activation during VF is apparently disorganized, making mapping and interpretation difficult. Prolonged mapping during VF would require mechanical circulatory support as VF causes complete hemodynamic collapse. These limitations have been addressed by the realization that there is often a reliable trigger arrhythmia that initiates the clinical VF episodes, and an approach to map and ablate this trigger can be successful. Such triggers can be PVCs localizing to the Purkinje/fascicular system, and in other cases can be ectopy from outflow tracts or intracavitary structures like papillary muscles, false tendons or moderator band, or can be monomorphic VT or preexcited atrial fibrillation that degenerate into VF. More recently, approaches beyond trigger elimination directly targeting the VF substrate have been devised. This includes elimination of the arrhythmogenic substrate localizing to the epicardial right ventricular outflow tract in patients with Brugada syndrome, akin to elimination of the arrhythmogenic substrate harbored by regions within scar in ischemic and non-ischemic cardiomyopathies. Further, recent attempts have been made to try to identify and ablate rotors during VF that may be important in perpetuating the VF episode. Such exciting advances in “curing” VF are proving to be life saving for resuscitated survivors of arrhythmic death.

Endocardial Device Leads in Patients with Patent Foramen Ovale: Echocardiographic Correlates of Stroke/TIA and Mortality: CIEDs AND PFO: STROKE/MORTALITY

Echocardiographically detected patent foramen ovale (PFO) has been associated with stroke/transient ischemic attack (TIA) in patients with cardiac implantable electronic devices (CIEDs). We sought to evaluate the relationship between echocardiographic characteristics and risk of stroke/TIA and mortality in CIED patients with PFO.

Management of cardiac implantable electronic devices during interventional pulmonology procedures

An increasing number of patients are receiving cardiac implantable electronic devices (CIED) now. Many of them need pulmonary procedures for various indications including, but not limited to, lung cancer and benign endobronchial lesions. Over the last two decades, interventional pulmonology (IP) has expanded its scope to include various modalities that use heat and electrical energy and in the process, create electromagnetic field in the vicinity. This raises concerns for electromagnetic interference (EMI) causing abnormal behavior in the CIEDs. While guidelines and recommendations on the peri-procedural management of CIEDs do exist, none of them directly address the pulmonary procedures. In this paper, we strive to review the available literature pertaining to the management of CIEDs in the context of EMI caused by the various IP procedures.

Regular tachycardia despite Wenckebach atrioventricular conduction

We present a 21-year-old woman status post orthotopic heart transplantation initially presenting with a regular narrow complex tachycardia at 159beats/min. With intravenous diltiazem the rhythm transitioned to a regular tachycardia at 106beats/min, 2/3rd of the initial heart rate. We demonstrate this to be a novel description of 3:2second-degree Mobitz type I atrioventricular block (Wenckebach) with the absence of the hallmark regularly irregular (grouped beating) pattern.

Drug-Induced Torsades de Pointes and Genetic Screening

Author Affiliations: Houston Veterans Affairs Center for Innovations in Quality, Effectiveness, and Safety, Michael E DeBakey Veterans Affairs Medical Center, Houston, Texas (Murphy, Meyer, Russo, Wei, Singh); Department of Medicine, Baylor College of Medicine, Houston, Texas (Murphy, Meyer, Russo, Wei, Singh); University of Texas Health Science Center at Houston’s School of Biomedical Informatics (Sittig); University of Texas–Memorial Hermann Center for Healthcare Quality and Safety, Houston (Sittig).