Stuart J. Connolly

Antiarrhythmic use from 1991 to 2007: Insights from the Canadian Registry of Atrial Fibrillation (CARAF I and II)

BACKGROUNDnThe pharmacologic management of atrial fibrillation (AF), the most common sustained cardiac arrhythmia, has been traditionally dichotomized into control of ventricular rate or re-establishment and maintenance of sinus rhythm.nnnOBJECTIVEnThe purpose of this study was to evaluate the use of rate-controlling drugs and antiarrhythmic drugs (AAD) in the Canadian Registry of Atrial Fibrillation (CARAF) over a 16-year period from 1991 through 2007.nnnMETHODSn1,400 patients with new-onset paroxysmal AF who were enrolled in CARAF were included in this analysis. We assessed trends in ventricular rate-controlling medication use (digoxin, beta-blockers, and calcium channel blockers) and AAD (class IA, IC, and III antiarrhythmic agents) at baseline and follow-up visits as well as by calendar year.nnnRESULTSnAAD use increased initially from 1991 to 1994 (peak use 42.5%) before steadily declining. Sotalol use decreased (27% to 6%), whereas amiodarone use increased (1.6% to 17.9%). Rate-controlling medication use decreased from 1991 to 1995 (54.1% to 34.1%) due to declining digoxin use (62.9% to 16.3%). After 1999, there was a continued increase in rate-controlling medication use (peak use 52.5% in 2007) due to increased beta-blocker use (17% to 45.7%). Calcium channel blockers use changed little over the duration of the study.nnnCONCLUSIONnThe management of AF has undergone significant shifts since 1990, reflecting the influence of drug development, prevailing belief systems, the impact of large clinical trials, and evidence-based recommendations. Monitoring of pharmacotherapy trends will provide insight into the real-world application of evidence-based guidelines as well as allow the opportunity to identify deficiencies and improve patient care.

Atrial fibrillation: guiding lessons from epidemiology

The epidemiology of AF is a challenging and surprising area of medical knowledge. The prevalence of AF may be not changing despite the common perception. It is possible that being earlier disease of the middle age, and because of changing etiology and successful treatment of underlying vascular conditions, AF is shifting to the elderly population. In this population, it becomes more clinically significant, and increasingly leads to disability and death. Screening procedures for silent AF likely are underimplemented and may change understanding of AF epidemiology significantly. Hypertension may be the most common primary etiology of AF, and the possibility of effective primary prevention of AF by strict control of hypertension needs to be evaluated adequately.

Switching Patients From Blinded Study Drug to Warfarin at the End of the ENGAGE AF-TIMI 48 Trial: Setting a New Standard

Interruption of warfarin treatment is associated with an increased risk of thromboembolic events [(1)][1]. Among patients with atrial fibrillation (AF) receiving warfarin for stroke prevention, as many asxa01 in 10 temporarily interrupt treatment each year,xa0most commonly for invasive procedures [(1,

Bilateral Pneumothorax Post Insertion of Intracardiac Defibrillator, a Rare Condition, Risk Factors and Prevention

TOUCH MEDICAL MEDIA Abstract The implantation cardiac rhythm management devices is rising annually. The two known common complications of these devices, infection and pneumothorax, occur in 1.2% and 0.6% of patients, respectively. Pneumothorax is usually seen in the ipsilateral part of implantation however in some rare cases this will be seen in the contralateral part. Despite using cephalic vein cutdown or venogram assisted puncture of axillary vein to reduce this complication, pneumothorax remains the one of the most morbid complications post implant. In this article a rare case of bilateral pneumothorax will be presented and discussed.

How Useful is Computed Tomography of the Chest for the Diagnosis of Asymptomatic Right Ventricular Perforation Following Pacemaker Insertion

TOUCH MEDICAL MEDIA Abstract Insertion of implantable cardiac devices such as pacemaker and defibrillators is one of the most common invasive procedures in cardiology. This procedure can be sometimes very challenging and needs more advanced modalities to diagnose the complication. In this article, we present a case of asymptomatic right ventricular perforation post pacemaker implantation who was diagnosed with CT scan and was managed further.

Evolving Indications for Permanent Pacing in Patients with Vasovagal Syncope

Patients with frequent vasovagal syncope are often resistant to medical therapy. Consensus statements from the United States and Great Britain [1,2] recommend dual chamber pacing for vasovagal syncope if patients have a positive tilt test ending in a relative bradycardia, and if pacing during a second tilt test prevents syncope. These recommendations were not tested until recently. There were concerns about how to select patients, that syncope detection algorithms are unproven, and that pacing might be unable to prevent symptoms due to vasodepression. Three recent nonrandomized studies [3–5] used pacemakers which sense initial drops in heart rate in order to activate early in the syncopal spell, and then pace at a relatively high rate. This acutely delivered relative tachycardia might provide for suf~cient cardiac output to overcome the effects of the vasodepression. One study used rate hysteresis and two used rate drop sensing. None of the studies required evidence that acute pacing during tilt testing prevented syncope. These studies showed a fairly uniform 75–90% reduction in the frequency of syncope. Given these promising results, we designed and are conducting the North American Vasovagal Pacemaker Study [6], a randomized clinical trial, to evaluate the effectiveness of dual chamber pacing with rate-drop sensing in patients at high risk of a recurrence of syncope.