Vikas Kuriachan, MD, FRCP(C), Fellow, Cardiac Arrhythmia, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB.
Robert Sheldon, MD, PhD, FRCP(C), Professor, Cardiac Sciences, and Associate Dean of
Clinical Research, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB.

The implantable cardioverter defibrillator (ICD) plays an important role in primary and secondary preventions of sudden cardiac death. Several trials conducted in the past few years have shown the superiority of ICDs over drug therapy. Cardiac resynchronization therapy (CRT) is also emerging as an adjunctive treatment for heart failure, with some survival benefits as well. This article reviews the major recent clinical trials of ICD and CRT devices and summarizes their importance in contemporary cardiology.
Key words: cardioverter defibrillator, cardiac resynchronization, older adults, sudden cardiac death, cardiology.

Jagdish Butany, MBBS, MS, FRCPC, Department of Pathology, Toronto General Hospital, University Health Network; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON.
Gursharan S. Soor, BSc, Department of Pathology, Toronto General Hospital, University Health Network, Toronto, ON.
Adriana Luk, BSc, Department of Pathology, Toronto General Hospital, University Health Network, Toronto, ON.
Anna Woo, MD, FRCPC, FACC, Hypertrophic Cardiomyopathy Program, Division of Cardiology, Toronto General Hospital; Department of Medicine, University of Toronto,Toronto, ON.
Anthony Ralph-Edwards, MD, FRCSC, Division of Surgery, Toronto General Hospital, University of Toronto, Toronto, ON.
Heather Ross, MD, FRCPC, Department of Medicine, Division of Cardiology, University of Toronto, Toronto General Hospital, Toronto, ON.

Hypertrophic cardiomyopathy (HCM) is an uncommon disease with significant consequences. Since the 1950s, major strides in understanding its etiology and pathogenesis have led to improved management and patient survival. Hypertrophic cardiomyopathy is associated with various mutations in several cardiac sarcomeric genes. Due to the complications of HCM, such as left ventricular outflow tract obstruction, diastolic dysfunction, arrhythmias, increased risk of stroke, infective endocarditis, and, most importantly, sudden cardiac death, appropriate and timely diagnosis is critical. This review summarizes current knowledge about HCM and the most appropriate investigations for persons suspected of having HCM. Treatment strategies for the disease and its complications are presented briefly.
Key words: hypertrophic cardiomyopathy, cardiomyopathy, sudden cardiac death, older adults.

Abdul Razakjr Omar, MBBS, MMed (Int Med), MRCP (UK), FAMS (Cardiology) Consultant Cardiologist, National University Hospital, Singapore.
Kumaraswamy Nanthakumar, MD, FRCPC, Staff Cardiologist, Cardiac Electrophysiologist, University Health Network, Toronto General Hospital; Assistant Professor of Medicine, University of Toronto, Toronto, ON.

In older patients the aging process is complicated by underlying comorbid diseases. An implantable cardioverter-defibrillator (ICD) has been shown to reduce mortality due to sudden cardiac death and improve survival in patients at risk of lethal arrhythmia. However, its role in older adults with coronary artery disease (CAD) is less well understood. A literature review of ICD trials was conducted, assessing efficacy and feasibility of the device in older adults.
The use of an ICD should be individualized in older patients. ICD therapy is feasible and safe in preventing sudden cardiac death. Age is insufficient to exclude an older adult with CAD from ICD therapy.
Key words: coronary artery disease, implantable cardioverter-defibrillator, sudden cardiac death, ventricular tachycardia, cardiac resynchronization therapy.