Epidemiology of gender-related differences of arrhythmias in the ICU

Background

Studies have revealed sex-specific differences in the electrophysiology with respect to rate, sinus node function, refractory periods, conduction time of accessory pathways and the type and duration of arrhythmias. However, data on sex-specific differences of arrhythmias are lacking in critically ill patients.

Aim of the study

From November 1996 until July 1999 a prospective study was conducted in the ICU of a university hospital to assess sex-specific differences in all consecutive tachyarrhythmias.

Results

278 episodes of tachyarrhythmia (wide QRS complex n = 168, narrow QRS complex n = 108, ventricular fibrillation n = 2) were recorded in 119 patients (83 m, 36 f, age 65 ± 12, APACHE II 19.6 ± 18). There was no significant sex-specific difference (P = 0.49) in the incidence of wide QRS complex tachycardia (100/168 vs 68/110) and narrow QRS complex tachycardia (66/168 vs 42/110). A significant gender-related difference, however, was detected in the etiology of narrow complex tachycardia: male patients exhibited a higher incidence in atrial fibrillation (AFIB) and atrial flutter (AFLU) while female patients suffered more frequently from supraventricular tachycardia (SVT; ie atrial, juctional or AV nodal reentry tachycardia) (P = 0.003). The incidence of mononomorphic ventricular tachycardias (VT) was comparable in both groups. Similarly, there was no significant difference in the rate of the tachyarrhythmias (204.5 ± 77/min vs 202 ± 74/min).

Conclusion

Data from this study show that there are gender-related differences in the type of tachyarrhythmia in critically ill patients. Whereas men were prone to AFIB and AFLU, female critically ill patients had a preponderance for regular SVT in this analysis. The distribution of VT was relatively homogeneous among sexes.

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