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Biomedical subjects

Martin S Green

Publications and source records attributed to Martin S Green.

16 recordsLinked to original sources
PubMed2006

Influence of gender on ICD implantation for primary and secondary prevention of sudden cardiac death.

AIMS: This study sought to investigate the influence of gender on access to ICD therapy and examine the influence of gender on subsequent ICD shock experience. METHODS AND RESULTS: The records of 353 consecutive patients (140 and 213 secondary prevention, respectively) who received their first ICD between January 2000 and March 2004 were reviewed. All patients fulfilled criteria for primary or secondary prevention ICD implantation. Baseline characteristics and ICD shock experiences were compared. Female patients were younger and less likely to have a history of ischaemic heart disease or atrial arrhythmias (P<0.01). In contrast, female patients were more likely to have heart failure and diabetes (P<0.01). Markedly fewer females received an ICD for either primary (M:F ratio 8.5:1, P<0.01) or secondary (M:F ratio 4.5:1, P<0.01) prevention. Further, significantly fewer female patients received an ICD for MADIT II indications (M:F 11.2:1, P<0.01). Over the mean follow-up of 1.8+/-1.1 years, gender had no influence upon the likelihood of receiving either an appropriate or an inappropriate shock (P=ns). CONCLUSION: Although male patients accounted for the great majority (85%) of all ICD recipients, there was no evidence of influence of gender on the likelihood of receiving an appropriate or inappropriate shock.

Adult↗
PubMed2006

Frequency of peripartum cardiomyopathy.

Reports from case series have estimated the incidence of peripartum cardiomyopathy (PC) at 1 case/1,485 live births to 1 case/15,000 live births and probable mortality rates of 7% to 60%. The objective of this study was to produce the first population-based study of the incidence, mortality, and risk factors for PC. The National Hospital Discharge Survey was used. Discharge information was available for 3.6 million patient discharges from 1990 to 2002. There were an estimated 16,296 cases of PC from 1990 to 2002. During this period, there were 51,966,560 live births in the United States. Thus, the incidence of PC was 1 case/3,189 live births. There was a trend toward an increase in PC incidence during the study period, with an estimate for the years 2000 to 2002 of 1 case/2,289 live births. The in-hospital mortality rate was 1.36% (95% confidence interval 0% to 10.2%). The total mortality rate was 2.05% (95% confidence interval 0.29% to 10.8%). Patients with PC were older (mean age 29.7 vs 26.9 years), were more likely to be black (32.2% vs 15.7%), and had a higher incidence of pregnancy associated hypertensive disorders (22.5% vs 5.87%) compared with national data. In conclusion, the incidence of PC is relatively uncommon, occurring at an average frequency of 1 case/3,189 live births from 1990 to 2002. The estimated mortality of 1.36% to 2.05% (95% confidence interval 0.29% to 10.8%) is less than previously reported from most case series.

Adolescent↗
PubMed2006

Universal access -- but when? Treating the right patient at the right time: access to electrophysiology services in Canada.

The Canadian Cardiovascular Society Access to Care Working Group has published a series of commentaries on access to cardiovascular care in Canada. The present article reviews the evidence for timely access to electrophysiology services. Using the best available evidence along with expert consensus by the Canadian Heart Rhythm Society, the panel proposed a series of benchmarks for access to the full scope of electrophysiology services, from initial consultation through to operative procedures. The proposed benchmarks are presented herein.

Canada↗
PubMed2006

Appropriate result from an inappropriate ICD shock.

A case of inappropriate detection of an ungrounded external AC current by an implantable cardioverter defibrillator (ICD) is reported. The resultant ICD shock dislodged the patient from the electrical source, thus preventing injury or electrocution.

Defibrillators, Implantable↗
PubMed2005

Acupuncture triggering inappropriate ICD shocks.

Acupuncture is a modality of alternative medicine popular certain sectors of society. The possible interaction between acupuncture and ICD therapy has not been previously investigated. A case of acupuncture triggering inappropriate shocks from the ICD is reported.

Acupuncture↗
PubMed2005

Long-term outcome of cardiac resynchronization therapy in patients with severe congestive heart failure.

BACKGROUND: Cardiac resynchronization therapy (CRT) has recently been shown to be an effective short-term therapy for patients with drug-refractory heart failure and intraventricular conduction delay. Little is known about the long-term effects of this therapy. OBJECTIVES: To determine the long-term outcome of all consecutive patients who underwent CRT at two Canadian centres, and to determine what baseline variables predict a response to CRT. RESULTS AND CONCLUSIONS: The present study comprised a total of 85 patients (mean age 66+/-9 years; 88% male) with New York Heart Association class II (4%), class III (84%) or class IV (12%) heart failure. All patients fulfilled the standard CRT indications with a QRS duration of 168+/-22 ms and a nuclear gated ejection fraction (EF) of 21+/-6%. Eighteen of the 85 patients were implanted with a combination automatic implantable cardioverter-defibrillator and CRT device. Within a mean clinical follow-up of 3.0+/-1.0 years, 26 of the 85 patients died, and eight patients underwent cardiac transplantation, with four transplant-related deaths (mean survival 3.53+/-0.26 years). Ten patients died of sudden cardiac death, eight patients died of progressive heart failure and eight patients died of noncardiac causes. None of the baseline factors (age, sex, EF, etiology, New York Heart Association class, QRS duration or implantable cardioverter-defibrillator) or indexes of CRT (change in EF or QRS duration) were predictive of a poor outcome. There was a clear trend for patients with a greater left ventricular EF gain to have a better outcome (P=0.1). The present observational data represent one of the longest follow-up databases of patients undergoing CRT. The significant morbidity and mortality found after CRT highlight the severity of the underlying cardiac pathology and concurrent illnesses.

Aged↗
PubMed2004

The association of left atrial size and occurrence of atrial fibrillation: a prospective cohort study from the Canadian Registry of Atrial Fibrillation.

BACKGROUND: The effect of left atrial (LA) dimension on the recurrence of atrial fibrillation (AF) has been examined in small studies. We evaluated the effect of LA dimension on the occurrence of AF using 2- and 4-year echocardiographic data in a large cohort of patients with new onset AF. METHODS: The Canadian Registry of AF (CARAF) enrolled subjects with AF at the first electrocardiographically confirmed diagnosis. Patients were classified at 2 and 4 years as no recurrent AF (No RAF), paroxysmal AF (PAF), or chronic AF (CAF) based on clinical symptoms and electrocardiographic documentation. The association between baseline, 2-, and 4-year LA dimensions with occurrence of AF as determined by echocardiography was evaluated using a multivariate analysis. RESULTS: The No RAF group (n = 176) had a significantly smaller LA dimension (36.9 +/- 6.8 mm) at baseline compared to the CAF group (n = 227) (42.8 +/- 7.5 mm, P <.0001). The No RAF and PAF (n = 153) groups did not have a significant change in LA dimension at 2 or 4 years. Only those with CAF had a significant increase in LA dimension at 2 and 4 years, +1.39 mm (95% CI 0.01-2.8) and +3.48 mm (95% CI 1.8-5.2), respectively. CONCLUSIONS: A larger baseline LA dimension is associated with progression to CAF. Patients with no or paroxysmal recurrence had no change in LA dimension over a 4-year period. These findings have implications in tailoring modes of therapy in patients with AF.

Aged↗
PubMed2004

Catheter cryoablation of supraventricular tachycardia: results of the multicenter prospective "frosty" trial.

OBJECTIVE: To study the safety, efficacy, and mapping utility of a new cryoablation catheter. BACKGROUND: The CryoCath Technologies Freezor catheter has been used successfully for cryoablation of supraventricular tachycardia (SVT), but has not been evaluated in a large clinical trial. METHODS: A multicenter clinical trial to evaluate the safety, efficacy, and cryomapping utility of this cryoablation catheter was conducted in 166 subjects. The target of ablation was the slow pathway in patients with SVT due to AV nodal reentry (AVNRT, n = 103), an accessory pathway in patients with AV reentrant SVT (AVRT, n = 51) and the AV junction in patients with atrial fibrillation (AF, n = 12). RESULTS: Acute procedural success (APS) was achieved in 83% of the overall group (95% CI, 76% to 88%). APS in the AVNRT group was 91% (98.3% CI, 82% to 97%), compared to 69% for AVRT (98.3% CI, 51% to 84%) and 67% for AF (98.3% CI, 29% to 93%), a highly significant difference (P < .001 by stepwise logistic regression). In patients with APS, long-term success after 6 months was 91% overall (95% CI, 86% to 96%) and 94% for AVNRT subjects (98.3% CI, 87% to 100%). None of the AVNRT or AVRT subjects required a permanent pacemaker. Cryomapping successfully identified ablation targets in 64% of patients in whom it was attempted. The electrophysiologic effects of cryomapping were completely reversible within minutes in 94% of such attempts. CONCLUSIONS: Catheter cryoablation of SVT is a safe alternative to RF ablation and is clinically effective in patients with AVNRT. Cryomapping can reversibly identify targets for ablation and can help minimize the risk of inadvertent AV block during ablation.

Adult↗
PubMed2004

Preexcitation masking underlying aberrant conduction: an atriofascicular accessory pathway functioning as an ectopic right bundle branch.

Preexcitation and aberrant conduction both cause a broad QRS complex. An unusual case of an atriofascicular accessory pathway effectively functioning as an ectopic right bundle branch and responsible for both physiologically normal ventricular activation and pathologic preexcited tachycardias as part of a split AV node-bundle branch system is presented.

Adult↗
PubMed2002

A cool ablation.

Explore the source record for details and available documents.

Adolescent↗
PubMed2002

PRKAG2 cardiac syndrome: familial ventricular preexcitation, conduction system disease, and cardiac hypertrophy.

Genetic studies of families with inherited cardiac rhythm disturbances have established a molecular basis for ventricular arrhythmogenic disorders. Genes responsible for the long QT syndrome, Brugada syndrome, and polymorphic ventricular tachycardia have been identified. The elucidation of genetic defects responsible for more commonly occurring supraventricular rhythm disturbances have not been as forthcoming, with the exception of SCN5A mutations known to cause conduction system disease. Recently, we identified the genetic cause of a familial arrhythmogenic syndrome characterized by ventricular preexcitation and tachyarrhythmias (Wolff-Parkinson-White syndrome), progressive conduction system disease, and cardiac hypertrophy. The causative gene was shown to be the gamma-2 regulatory subunit (PRKAG2) of AMP-activated protein kinase. The role of AMP-activated protein kinase in the regulation of the glucose metabolic pathway in muscle suggests that genetic defects in PRKAG2 may induce a previously undescribed cardiac glycogenosis syndrome.

AMP-Activated Protein Kinases↗