Gender differences in arrhythmias

Electrocardiographic and electrophysiologic differences between men and women have long been noted. Women have a higher intrinsic heart rate than men, along with a longer corrected QT interval and a shorter sinus nodal recovery time. The incidence of and risk factors for a variety of arrhythmias differ between men and women. Atrioventricular nodal reentry tachycardia has a 2:1 female-to-male predominance, while accessory pathways are twice as frequent in men. Although atrial fibrillation is more prevalent in men of all age groups, the absolute numbers of men and women with atrial fibrillation are equal, and the associated morbidity and mortality experienced by women with atrial fibrillation appear to be worse. Women have a lower incidence of sudden cardiac death, and female survivors of sudden cardiac death have a lower frequency of spontaneous or inducible ventricular tachycardia. On the other hand, drug-induced torsade de pointes and symptomatic long QT syndrome have a female predominance. Therefore, greater caution should be used when prescribing QT-prolonging drugs in women. The incidence of arrhythmias is increased during pregnancy, and management of pregnant patients poses a significant challenge. The mechanisms of these gender differences are unclear but may be related to hormonal effects and the shorter QT interval in adult males. Pharmacologic and nonpharmacologic therapies are usually equally efficacious, but the risks of pharmacologic therapy are different in men and women. Atrial fibrillation may be more difficult to treat in women.     

The coeliac iceberg in Italy. A multicentre antigliadin antibodies screening for coeliac disease in school-age subjects

Background : Recent studies suggest that coeliac disease (CD) is one of the commonest, life-long disorders in Italy. The aims of this multicentre work were: (a) to establish the prevalence of CD on a nationwide basis; and (b) to characterize the CD clinical spectrum in Italy. Patients and methods : Fifteen centres screened 17201 students aged 6–15 years (68.6% of the eligible population) by the combined determination of serum IgG- and IgA-antigliadin antibody (AGA) test; 1289 (7.5%) were IgG and/or IgA-AGA positive and were recalled for the second-level investigation; 111 of them met the criteria for the intestinal biopsy: IgA-AGA positivity and/or AEA positivity or IgG-AGA positivity plus serum IgA deficiency. Results : Intestinal biopsy was performed on 98 of the 111 subjects. CD was diagnosed in 82 subjects (75 biopsy proven, 7 not biopsied but with associated AGA and AEA positivity). Most of the screening-detected coeliac patients showed low-grade intensity illness often associated with decreased psychophysical well-being. There were two AEA negative cases with associated CD and IgA deficiency. The prevalence of undiagnosed CD was 4.77 × 1000 (95% CI 3.79–5.91), 1 in 210 subjects. The overall prevalence of CD, including known CD cases, was 5.44 × 1000 (95% CI 4.57–6.44), 1 in 184 subjects. The ratio of known to undiagnosed CD cases was 1 in 7. Conclusions : These findings confirm that, in Italy, CD is one of the most common chronic disorders showing a wide and heterogeneous clinical spectrum. Most CD cases remain undiagnosed unless actively searched.     

Evaluation of the patient with syncope

The evaluation of the syncopal patient is often expensive and may not yield a specific diagnosis. An understanding of the cardiac and noncardiac causes of syncope can be helpful in making a specific goal-oriented evaluation of these patients.     

Atrial fibrillation in patients with heart failure

Atrial fibrillation and heart failure are very common cardiac disorders, and both are associated with symptoms, significant morbidity, and mortality. Studies have attempted to determine the prognostic significance of atrial fibrillation in patients with heart failure. Whether atrial fibrillation is an independent risk factor of mortality remains controversial. Multiple trials using either pharmacologic or nonpharmacologic therapies in an attempt to manage atrial fibrillation have been developed. The purposes of this review are to present an overview of atrial fibrillation in patients with heart failure and to discuss the prevalence, prognostic significance, complications, mechanisms, and trials that have formed the therapies presently used.     

Amiodarone: What have we learned from clinical trials?

Amiodarone is an antiarrhythmic agent commonly used in the treatment of supraventricular and ventricular tachyarrhythmias. This paper reviews clinical trials in which amiodarone was used in one of the treatment arms. Key post-myocardial infarction trials include EMIAT and CAMIAT, both of which demonstrated that amiodarone reduced arrhythmic but not overall mortality. In patients with congestive heart failure (CHF), amiodarone was associated with a neutral survival in CHF/STAT and improvement in survival in GESICA. In patients with nonsustained ventricular tachycardia, the MADIT trial demonstrated that therapy with an implantable cardioverter-defibrillator (ICD) improved survival compared with the antiarrhythmic drug arm in such patients, most of whom were taking amiodarone. In sustained VT/VF patients, the CASCADE trial demonstrated that empiric amiodarone lowered arrhythmic recurrence rates compared with other drugs guided by serial Holter or electrophysiologic studies. Several trials including AVID, CIDS, and CASH have demonstrated the superiority of ICD therapy compared with empiric amiodarone in improving overall survival. Clinical implications of these trials are discussed.     

Acute treatment of atrial fibrillation: spontaneous conversion rates and cost of care

Acute treatment of atrial fibrillation is costly although spontaneous conversion rates are high. We reviewed 114 patients admitted to our inpatient service via the emergency department with a principal diagnosis of atrial fibrillation and found the spontaneous conversion rate was 50% in 48 hours, the average length of stay was 3.9 +/- 5.2 days, and the average cost was $6,692 +/- $4,928.     

Adolescents with type 1 diabetes and risky behaviour

Aim: The aim of the student is to assess whether adolescents with type 1 diabetes mellitus (T1DM) in Italy differ from their healthy peers in regard to risky behaviour. Methods: Data were collected from 215 patients, aged 14 ± 2 years with a mean disease duration of 7 ± 5 years. The control group was comprised of 464 healthy adolescents recruited among high school students. Each patient completed an anonymous confidential questionnaire to determine the prevalence of sexual behaviour, alcohol and tobacco consumption, illicit drug use, and, among patients with diabetes and frequency of mismanagement related to diabetes care. Results: Compared with controls, subjects with diabetes showed a similar rate of sexual intercourse among males and lower rates among females (34.8% vs 35.5%, p NS and 29.4% vs 41.4%, p < 0.05, respectively). Males in the diabetes group reported a higher rate of tobacco use, whereas females showed similar or higher rates of use for every illicit drug studied. Among patients with diabetes, those who are engaged in risky behaviour showed a higher rate of treatment mismanagement (76% vs 34%, p < 0.01). Conclusion: Adolescents with T1DM are as likely as their healthy peers to engage in risky behaviour, indicating the potential benefit of anticipatory guidance concerning glycaemic control and increased risk of acute and chronic complications.     

Assessment of antiarrhythmic drug efficacy in the treatment of supraventricular arrhythmias

Few guidelines exist for judging the efficacy of antiarrhythmic drugs in patients with supraventricular arrhythmias. Useful definitions concerning the frequency and duration of supraventricular arrhythmias are offered, and complete and partial efficacy criteria are outlined for noninvasive electrocardiographic and invasive electrophysiologic techniques. Several open label, double-blind, parallel and crossover study designs are suggested for efficacy studies concerning the termination and prevention of supraventricular tachycardia. These recommendations are useful for designing new drug trials needed to evaluate properly the efficacy of antiarrhythmic agents in the treatment of various supraventricular arrhythmias.