Rakesh Gopinathannair

Delayed maximal response to left cardiac sympathectomy for catecholaminergic polymorphic ventricular tachycardia

A 22-year-old man with multiple defibrillator shocks for catecholaminergic polymorphic ventricular tachycardia (CPVT) refractory to medical therapy underwent thoracoscopic left cardiac sympathectomy (LCS). Serial follow-up exercise tests showed delayed response with complete arrhythmia suppression and markedly improved exercise tolerance 3 months after the procedure. Left cardiac sympathectomy is a minimally invasive procedure that can reduce recurrent CPVT. The maximal effect of LCS may be delayed suggesting remodelling of cardiac sympathetic innervation.

The dual role of implantable loop recorder in patients with potentially arrhythmic symptoms: a retrospective single-center study.

Background: Unexplained and potentially arrhythmic symptoms often lead to electrophysiology referral for evaluation. Implantable loop recorder (ILR) correlation of the symptom to the rhythm can secure a definitive arrhythmic diagnosis after a standard, yet nondiagnostic workup.

Slower Heart Rates for Healthy Hearts Time to Redefine Tachycardia

The management of atrial fibrillation, even in the modern era, remains complex and challenging. Preventing atrial fibrillation occurrence by identifying and favorably improving modifiable risk factors thus assumes great importance. It is well known that hypertension and resultant structural heart disease contributes significantly to the incidence of atrial fibrillation.1,2 The Losartan Intervention For End point reduction in hypertension (LIFE) study thus far has shown us that angiotensin-receptor blockade and reduction in left ventricular hypertrophy, irrespective of blood pressure–lowering, reduces the incidence of new-onset atrial fibrillation.1,3 Article see p 337 In recent years, accumulating evidence has linked high resting sinus heart rates (HR) directly and indirectly to adverse cardiovascular outcomes.4,5 Epidemiological studies show resting HR to be an independent predictor of cardiovascular and all-cause mortality in general population as well as in hypertensive patients.6 The cardiovascular benefits offered by β-blockade in coronary artery disease and heart failure have, in part, been attributed to β-blocker–mediated HR reduction.7,8 Other studies have linked high baseline HR to the development of hypertension, to the progression of coronary artery disease, and to the triggering of myocardial infarction, ventricular dysfunction, and ventricular arrhythmias.6,9–11 In this issue of Circulation: Arrhythmia and Electrophysiology , Okin and colleagues12 examines the relationship of HR changes over time on risk of atrial fibrillation in hypertensive patients as part of the LIFE study. In this post hoc analysis of the prospective LIFE study, 8828 hypertensive patients with left ventricular hypertrophy by ECG but without a history of atrial fibrillation were followed for a mean of 4.7±1.1 years. New onset atrial fibrillation was determined by 12-lead ECG performed on an intermittent, infrequent basis (at baseline, 6 months, and yearly thereafter). Hypertension was treated with losartan or atenolol. Using a variety of analyses, higher in-treatment HR on serial …

Ibutilide revisited: stronger and safer than ever

When the cardioversion of atrial fibrillation is contemplated, many clinicians think only of one thing: electrical (DC) cardioversion. There are many reasons for this: (i) in most settings, the protocols to perform DC cardioversion are well established, easy to do, inexpensive, and efficient; (ii) manpower needed to perform DC cardioversion is relatively small; (iii) while no randomized controlled clinical trial demonstrates benefit, DC cardioversion is well established, carries a low risk, and is highly successful for most patients; and (iv) there is hardly a reason to think of any other alternative approach. On the other hand, several oral and intravenous drugs are available, and have been used effectively, to convert patients from atrial fibrillation to sinus rhythm. Why is this approach so often ignored? The reasons are somewhat complex: (i) the technique takes time even for the use of intravenous medications; (ii) pharmacological cardioversion is generally not as effective as DC cardioversion; (iii) more manpower is needed to manage patients for additional hours in many cases; (iv) protocols are not as well established and, therefore, undefined risks for the patient may occur; and (v) there are potential proarrhythmic risks for all anti-arrhythmic medications. Previous randomized controlled clinical trials have demonstrated the potential efficacy of anti-arrhythmic drugs to return patients to sinus rhythm using a ‘pill-in-the-pocket’ or intravenous infusion technique.1–3 Ibutilide, a class III anti-arrhythmic, is a potent blocker of the rapid component of the cardiac-delayed rectifier potassium current and also activates … *Corresponding author. Tel: +1 319 356 2344; fax: +1 319 384 6247, E-mail address : brian-olshansky{at}uiowa.edu

DAVID II did not slay Goliath.

The DAVID II (Dual Chamber and VVI Implantable Defibrillator II) trial tested two bradycardia programming modalities for a population of patients who received dual-chamber implantable cardioverter-defibrillators (ICDs) but had no clear indication for pacing. Two key questions arise when one

Not so innocent bystander(s)

A patient with atrial flutter, intermittent non-sustained wide complex tachycardia and 1:1 AV conduction is reported. Electrophysiology testing showed counterclockwise isthmus-dependent right atrial flutter with conduction via the AV node and an innocent bystander left lateral accessory pathway. This explained the observed intermittent wide complex tachycardia. After successful bidirectional cavotricuspid isthmus conduction block, a sustained wide complex tachycardia with identical counterclockwise right atrial activation and rate occurred. This was due to antidromic AV re-entrant tachycardia with innocent bystander activation of the right atrium mimicking atrial flutter. Accessory pathway ablation effectively stopped tachycardia.

Implantable Cardiac Monitors: Evolution Through Disruption

Syncope and stroke are commonly seen in clinical practice, and the diagnostic workup is often time-consuming and costly and may increase resource utilization in the health-care system. The use of implantable cardiac monitors (ICMs) in syncope evaluation has been well studied, but their use in cryptogenic stroke evaluation and anticoagulation management in patients with atrial fibrillation (AF) is still emerging. The standard workup of the syncope patient or those at risk for a possible cardioembolic stroke includes the utilization of external cardiac monitors; however, these devices cannot provide long-term arrhythmia assessment, whereas ICMs can now last up to three years, increasing the possibility of arriving at a diagnosis. Recent studies have shown that ICM use may shorten the time to diagnosis associated with AF, which may affect the prescribed treatment plan, thereby reducing the risks of further stroke. Long term and on a larger scale, this could potentially reduce overall health-care costs, but more studies are needed to confirm whether ICMs can positively decrease such costs and improve patient care. Still, these devices have become smaller and more reliable; additionally, they are now equipped with enhanced diagnostic capabilities, reducing the likelihood of physicians being confronted with an overwhelming amount of data, and supplying them with actionable items to improve patient care. With this growth, ICMs have in effect become a disruptive technology, as their applications in clinical practice continue to grow. Additional studies are warranted to investigate the safety and efficacy of their potential uses.