sudden cardiac death; Sudden Cardiac Death; Rural South India; octogenarians
Limited data exist on outcomes in very elderly ICD recipients. We describe outcomes in new ICD and Cardiac Resynchronisation Therapy with Defibrillator (CRT-D) implants in octogenarians at our institution.
Patients aged 80 years and above who underwent de novo ICD or CRT-D implantation from January 2006 to July 2012 were identified. Clinical data were collected from the procedural record, medical and ICD notes. Baseline characteristics were compared using independent sample t test for continuous variables and Fisher's exact test for categorical variables. Kaplan-Meier curves were constructed.
Ten per cent of all new ICD/CRT-D implants were aged 80 years and over. Median age was 83.0 years. Median follow-up was 29 months. Death occurred in 17 (34%). Median time to death was 23 months. Three deaths (6%) occurred within 12 months of ICD implantation. Appropriate therapy (ATP or shock) occurred in 19 (38%). Inappropriate therapy occurred in 6 (12%).
Rates of appropriate shocks and inappropriate therapy (shocks and ATP) and significant valvular incompetence were higher amongst deceased patients (P=0.03 OR 5.9 95% CI 1.3-27) and (P=0.02 OR 12 95% CI 1.3-112). Univariate analysis identified diuretic use (P=0.008 95% C.I. 0.05 to 0.63) and appropriate shock (P= 0.025 95% C.I. 1.25 to 26.3) as predictors of mortality.
Octogenarians make up a small but increasing number of ICD recipients. This study highlights high survival rates at one year with acceptable rates of appropriate and inappropriate device therapy. Ongoing debate regarding the appropriateness of ICD in very elderly patients is warranted.
sudden cardiac death; implantable defibrillators; octogenarians
Heart failure; defibrillator; sudden death
Despite ACC/AHA guidelines indicating implantable cardioverter defibrillator (ICD) as class I therapy for primary prevention of sudden cardiac death in patients with EF≤35%, ICD utilization rates in real world practice have been low.
To determine the rate of ICD implantation at a tertiary care academic center and to assess the reasons for under-utilization of the same.
Review of a prospectively collected database which included all patients diagnosed with an EF≤35% was performed to assess the rate of ICD implantation and mortality. Reasons for non-implantation of ICD were then assessed from detailed chart review.
A total of 707 patients (age 69.4 ± 14.1 years) with mean EF of 26±7% were analyzed. Only 28% (200/707) of patients had ICDs implanted. Mortality was lower in the group with ICD (25% vs 37%, p=0.004). When patients who either died or were lost to follow-up prior to 2005 were excluded, ICD utilization rate was still low at 37.6%. The most common reason for non-implantation of ICD was physicians not discussing this option with their patients. Patient refusal was the second most common reason.
ICD Implantation rates for primary prevention of SCD in patients with EF≤35% is low. Physician and patient education should be addressed to improve the utilization rates.
Implantable cardioverter-defibrillator; Outcomes; sudden cardiac death
Syncope; defibrillator; electrophysiology study
Syncope in elderly patients with heart disease is a growing problem. Its aetiological diagnosis is often difficult. We intended to investigate the value of the electrophysiological study (EPS) in old patients with syncope and heart disease.
EPS was performed in 182 consecutive patients with syncope and heart disease, among whom 62 patients were ≥75 years old and 120 patients <75.
Left ventricular ejection fraction was 43.9±11.7% in patients ≥75 and 41.1±12.6% in patients <75. During EPS, induced sustained ventricular arrhythmias were as frequent in both groups (27.4% in patients ≥75 versus 27.5% in patients <75, p=0.99) whereas AV conduction abnormalities were more frequent in older patients (37.1% in patients ≥75 versus 18.3% in patients <75, p<0.005). Syncope remained unexplained in 35.5% of patients ≥75 and in 51.7% of patients <75 (p>0.04). ICD was more likely to be implanted in younger patients than in patients ≥75 years (37.5% vs 21% respectively, p<0.009). During a mean follow-up period of 3.3±3 years, the 4-year-survival rate was 66.9±6.8 % in patients ≥75 and 75.9±6.2 % in patients <75 years. The main cause of death was heart failure in both groups. The factors related to a worse outcome in a multivariate analysis were low LVEF and higher age.
Complete EPS allows the identification of treatable causes in a high proportion of elderly patients with syncope and heart disease. Yet, the prognosis of these patients is mainly related to LVEF and age.
syncope; heart disease; electrophysiological study; elderly
In spite of their relative rarity, inheritable arrhythmias have come to the forefront as a group of potentially fatal but preventable cause of sudden cardiac death in children and (young) adults. Comprehensive management of inherited arrhythmias includes diagnosing and treating the proband and identifying and protecting affected family members. This has been made possible by the vast advances in the field of molecular biology enabling better understanding of the genetic underpinnings of some of these disease groups, namely congenital long QT syndrome, catecholaminergic polymorphic ventricular tachycardia and Brugada syndrome. The ensuing knowledge of the genotype-phenotype correlations enables us to risk-stratify, prognosticate and treat based on the genetic test results. The various diagnostic modalities currently available to us, including clinical tools and genetic technologies, have to be applied judiciously in order to promptly identify those affected and to spare the emotional burden of a potentially lethal disease in the unaffected individuals. The therapeutic armamentarium of inherited arrhythmias includes pharmacological agents, device therapies and surgical interventions. A treatment strategy keeping in mind the risk profile of the patients, the local availability of drugs and the expertise of the treating personnel is proving effective. While opportunities for research are numerous in this expanding field of medicine, there is also tremendous scope for incorporating the emerging trends in managing patients and families with inherited arrhythmias in the Indian subcontinent.
Channelopathies; Inherited Arrhythmias
A 32-year-old man underwent catheter ablation of an orthodromic atrioventricular reentrant tachycardia. The sinus rhythm electrocardiogram exhibited a normal PQ interval and no delta waves, but atrial pacing produced a prolonged PQ interval and wide QRS morphology with right bundle-branch block due to antegrade accessory pathway (AP) conduction. During the tachycardia, atrial double potentials consisting of the coronary sinus musculature (CSM) and left atrial (LA) potentials were observed. Ventricular extrastimulation exhibited retrograde decremental conduction with an identical atrial activation sequence as during the tachycardia. A radiofrequency application within the posterolateral CS during ventricular pacing eliminated the CSM-LA conduction and concomitantly the ventriculoatrial conduction via the AP was abolished. In this case, the CSM was associated with the bidirectional decremental conduction properties of the AP, and the antegrade slow conduction resulted in the absence of a shortening of the PQ interval and delta waves during sinus rhythm despite the continuous presence of antegrade AP conduction.
accessory pathway; decremental conduction property; coronary sinus musculature; atrial double potential; catheter ablation; atrioventricular reentrant tachycardia
Sudden cardiac death; arrhythmia; implantable cardioverter-defibrillator
Neurosurgical Drill; arrhythmia; Entrapped Pacing Leads
A 58 year old gentleman with complaints of palpitations and documented tachycardia was found to have a dilated right atrium, right ventricle and coronary sinus, which were due to partial unroofed coronary sinus without a left superior vena cava. He had upper septal ventricular tachycardia and atrio-ventricular nodal reentrant tachycardia, which was successfully treated by radiofrequency ablation.
partial unroofed coronary sinus; dilated coronary sinus; tachycardia
The "gap phenomenon" is an interesting phenomenon in electrophysiology arising from the differences in refractory periods at two or more levels of the atrioventricular (AV) conduction system. We present a patient with dual AV nodal physiology in whom the AH jump mediates the gap phenomenon. We also briefly discuss the other mechanisms of gap phenomenon that have been described in this setting.
gap phenomenon; Atrial Extrastimuli
Lead induced transient right bundle branch block is not uncommon during pacemaker implantation. We describe a patient with old anterior wall myocardial infarction with severe left ventricular dysfunction presenting with recurrent ventricular tachycardia who developed transient right bundle branch block and pseudomyocardial infacrction pattern during AICD implantation.
Pseudo Myocardial Infarction; AICD implantation
A 74-year old was considered for atrioventricular (AV) nodal ablation in view of atrial fibrillation (AF) with poorly controlled ventricular rate despite being on amiodarone. Targeted AV nodal ablation was successfully performed after identifying the target site for ablation by reviewing an ultra high-density map of the His region produced by automatic electrogram annotation.
His bundle; atrioventricular node; cardiac mapping; catheter ablation
arrhythmogenic right ventricular dysplasia
The expanding clinical indications of cardiac rhythm management have led to an increased use of pacemaker implantation which is associated with increased incidence of pacemaker infections. Staphylococcus aureus and epidermidis account for the vast majority of pacemaker infections. Pacemaker infection due to Mycobacterium tuberculosis (M. tuberculosis) is very rare, only few cases having been reported till date.
We describe here a study of three patients of pacemaker pocket infection with M. tuberculosis.
The possibility of mycobacterial pacemaker infection should always be kept in mind in patients with delayed pacemaker infection.
Mycobacterium tuberculosis; Pacemaker Infection
A 46-year-old man after a tricuspid valve replacement due to traumatic severe tricuspid regurgitation developed cavotricuspid isthmus-dependent counterclockwise atrial flutter. During a linear ablation using a contact force-sensing irrigated ablation catheter, the flutter could be terminated by a radiofrequency application within a deep pouch just below the bioprosthetic tricuspid valve.
Cavotricuspid isthmus-dependent atrial flutter; Contact force vector; Tricuspid valve replacement; Catheter ablation
Fragmented QRS; Chagas' disease
Cardiac Implantable Electronic Devices; Infections
His bundle; cryoablation
A 53-year-old man underwent implantation of a totally subcutaneous ICD (S-ICD; Boston Scientific). He was positioned supine, with the left arm abducted, externally rotated (i.e. palm up) and strapped to the arm extender. The generator was placed in the left mid-axillary line along the 5th-6th intercostal spaces and the defibrillation coil was tunneled anterior to the sternum. Defibrillation threshold (DFT) testing with 65 Jcaused a forceful pectoralis twitch. The patient woke up with a painful anteriorly dislocated left shoulder. Glenohumeral dislocation due to DFT testing has not been previously reported. It is likely that this complication is specific to the S-ICD implantation, and is related to positioning with the arm abducted, externally rotated, and immobilized, and use of greater defibrillation energy with current pathway through the bulk of the pectoralis muscle.Precautions may include extending the arm palm down, strapping the arm loosely, and adduction of the arm for DFT testing.
Subcutaneous implantable cardioverter-defibrillator; defibrillation threshold testing; shoulder dislocation; complication; device implantation
A 62-year-old man admitted for presyncope presented two symptomatic sustained ventricular tachycardia with right bundle branch morphology and inferior axis suggesting a pathology of the left ventricular lateral wall, the site where Cardiac Magnetic Resonance demonstrated a thinned, hypokinetic segment with fibro-fatty subepicardial infiltration. A very localized Left Dominant Arrhythmogenic Cardiomyopathy was diagnosed and an ICD implanted.
Arrhythmogenic Cardiomyopathy; Ventricular Tachycardia; Cardiac Magnetic Resonance
Fragmented QRS; Chagas' disease