Barriers to patients eligible for screening investigations and insertion of primary prevention implantable cardioverter defibrillators.

AIMS: Primary prevention (PP) implantable cardioverter defibrillator (ICD) implant rates in the UK are below national targets and barriers to this are not well known. This study was designed to identify the stages along the referral pathway from general to specialist care that eligible patients reach and what proportion eventually receive an ICD. METHODS AND RESULTS: A single institution database search was performed to identify all adults with severe left ventricular systolic dysfunction (left ventricular ejection fraction, LVEF≤35%), documented in the calendar year 2007. Medical records were assessed for age, heart failure aetiology, QRS duration, evidence of non-sustained ventricular tachycardia on Holter, electrophysiological study, and records of consultation with general physicians, cardiologists, and electrophysiologists (EPs) and reference to assessment of risk of sudden cardiac death and the role of ICD implantation. Three hundred twenty-six patients with LVEF ≤ 35% were identified from three electronic databases. Mean age was 72 ± 12 years. Seventy-two patients satisfied UK National Institute for Clinical Excellence guidelines for PP ICD implantation and 63 eligible for further screening. Of the 135 patients, 76 (56%) patients reviewed by a general cardiologist did not receive ICD implantation or referral for further assessment. When offered, ICD acceptance rate was high (35 vs. 3 patients who refused ICD). After seeing an EP, 8 of 47 (17%) patients were not offered ICD or further screening. The average age was 66.5 ± 6.2 years and no patient greater than 80 years had a PP ICD. CONCLUSIONS: Failure to refer from the general physician to cardiology and from the cardiologist to EP is the principle reason for low PP ICD implant rates among eligible patients in the UK.

A review of mitral isthmus ablation.

Mitral isthmus ablation forms part of the electrophysiologist's armoury in the catheter ablation treatment of atrial fibrillation. It is well recognised however, that mitral isthmus ablation is technically challenging and incomplete ablation may be pro-arrhythmic, leading some to question its role. This article first reviews the evidence for the use of adjunctive mitral isthmus ablation and its association with the development of macroreentrant perimitral flutter. It then describes the practical techniques of mitral isthmus ablation, with particular emphasis on the assessment of bi-directional mitral isthmus block. The anatomy of the mitral isthmus is also discussed in order to understand the possible obstacles to successful ablation. Finally, novel techniques which may facilitate mitral isthmus ablation are reviewed.

Concealed conduction of premature ventricular complexes resulting in AV nodal block.

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Exercise-induced syncope in a 22-year-old man.

CLINICAL INTRODUCTION: A 22-year-old man was referred to us for syncope during a game of Captain's ball. There was no prodrome. His friends did not notice any ictal movements. He was otherwise well prior to passing out. He was not taking any medications or supplements. He was not usually physically active, but was otherwise well with no significant medical history. This is his first episode of syncope. There was no history of cardiac arrest or seizures. There is no family history of premature sudden cardiac death.Physical examination was normal. ECG at rest demonstrated sinus rhythm with corrected QT interval of 400 ms. Echocardiography revealed a structurally normal heart. Holter monitoring was normal. Treadmill exercise stress test demonstrated the following rhythm on figure 1 during stage 4 Bruce protocol. Stress test was terminated in view of sustained arrhythmia as illustrated. He felt light-headed during the period, but otherwise felt that he could carry on with the exercise. ECG during recovery was unremarkable.

Recurrent AICD shocks in a 60-year-old man.

CLINICAL INTRODUCTION: We present the case of a 60-year-old man with history of non-ischaemic cardiomyopathy with left ventricular ejection fraction of 40%. His baseline surface 12-lead ECG shows sinus rhythm with PR interval of 170 ms, no evidence of pre-excitation and a normal QT interval. He had a single-chamber automated implantable cardiac defibrillator (AICD) inserted for sustained wide complex tachycardia associated with palpitations. Subsequently, he presented with recurrent shocks from the AICD coming on at rest despite treatment with amiodarone. He did not experience any significant cardiovascular symptoms except for mild palpitations. There were no reversible causes found for his arrhythmia. Figure 1 shows the device EGM of the event leading to the shock. QUESTION: What is the tachycardia that caused the AICD shock? (figure 1) Atrial fibrillation (AF) with pre-excitationVentricular fibrillation (VF)Multiform ventricular tachycardia (VT)Atrial tachycardia (AT) with bundle branch blockTorsades de Pointes (TdP).