Diphenhydramine and QT prolongation - A rare cardiac side effect of a drug used in common practice.

There have been few cases in recent times where QT interval prolongation has been studied with regards to the use of diphenhydramine. We present a case of a patient who presented because of shortness of breath and needed emergent hemodialysis; during the course of which he developed prolonged QT interval on electrocardiography, which was correlated interestingly with the use of diphenhydramine. Pruritus is a common symptom experienced by dialysis patients. A less known, but rare side effect of diphenhydramine is prolongation of QT interval. The histamine H1 receptor antagonist diphenhydramine inhibits the fast sodium channels and at higher concentrations inhibits the repolarizing potassium channels which leads to prolongation of the action potential and the QT interval. Diphenhydramine toxicity is dose-dependent with a critical dose limit of 1.0 g. Although a lot is known about the potential side effects of antihistamines, only a few cases have cited the cardiac side effects. Thus, it is important for the clinician to be aware of this potentially serious consequence of a commonly used drug, especially in the end-stage renal disease population. It is important for clinicians to be aware of this rare yet dangerous side effect of diphenhydramine. .

The development of aortic insufficiency in continuous-flow left ventricular assist device-supported patients.

BACKGROUND: Significant aortic insufficiency (AI) after left ventricular assist device (LVAD) placement affects device performance and end-organ perfusion. This study examined the development and progression of AI after implantation of continuous-flow LVAD. METHODS: Seventy-nine patients undergoing Heart Mate II (Thoratec Corp, Pleasanton, CA) LVAD implantation for predominantly destination therapy (n = 69 [87%]) were examined. Preoperative and postoperative echocardiograms for all patients were reviewed at the intervals of 0 to 3, 3 to 6, 6 to 12, 12 to 18, and 18 to 24 months. AI was graded on an interval scale of 0, none; 0.5, trivial; 1, mild; 1.5, mild to moderate; 2, moderate; 2.5, moderate to severe; and 3, severe. Development and progression of AI were analyzed. RESULTS: The incidence of significant AI (mild or greater) was 52% (n = 41). Median time to AI development was 187 days. The median duration of VAD support was 761 days. Mild AI developed in 41 patients (52%). No severe AI developed. In the Cox regression model (hazard ratio [95% confidence interval]), aortic valve closure (2.51 [1.06 to 5.89]; p = 0.03), and age (1.04 [1.008 to 1.08]; p = 0.01) were independent predictors of AI development. There was no difference in mortality rates in the two groups (p = 0.40 by log-rank test). A mixed-model linear regression analysis showed a significant overall progression of AI over time (ß ± standard error, 0.06 ± 0.02; p = 0.006). CONCLUSIONS: AI develops over time in a significant number of Heart Mate II LVAD patients. AI is more common in patients with closed aortic valves and in the older age group. As more patients require long-term VAD support, the development of AI will need careful attention and monitoring.

Intermittent aortic insufficiency as an aid to diagnosing obstruction in a HeartMate II continuous-flow left ventricular assist device.

This report details two cases of left ventricular assist device (LVAD)-related fungal infection. In both cases, the infection occurred within the device and formed an obstruction resulting in intermittent variation in the output of the LVAD. This was manifested by a change in the pattern of aortic insufficiency (AI) from continuous to intermittent on transesophageal echocardiography. Recognition of this finding may allow for noninvasive diagnosis of LVAD flow obstruction.

Systemic hypertension among women with uterine leiomyomata: potential final common pathways of target end-organ remodeling.

The uterus and the heart share a common structure and may remodel in a similar fashion, albeit temporally distinct. The authors investigated the prevalence of systemic hypertension in women with uterine leiomyomata (fibroids) and compared the prevalence in women undergoing hysterectomy for other reasons as well as in age-matched women from the National Health and Nutrition Examination Survey III (NHANES III). A total of 584 women, 205 with leiomyomata in 1999 (group A) and 379 who underwent hysterectomy for a variety of reasons in 2000 (group B) at Advocate Christ Medical Center were included. Presence of leiomyomata was confirmed by pathology. Hypertension was defined as blood pressure > or = 140/90 mm Hg or history of hypertension with or without medication use. The prevalence of hypertension in group A and B patients with leiomyomata compared with NHANES III overall was 48.6% vs. 24% (p<0.001), in African Americans 55.5% vs. 32.4% (p<0.001), and in Caucasians 51.1% vs. 23.3% (p<0.001). Leiomyomata were more frequent among hypertensive than normotensive women (57% vs. 27%). Caucasian and African-American women with leiomyomata were significantly younger and more likely to use hormone replacement therapy than others. Thus there appears to be an association between leiomyomata and hypertension, which needs to be explored in future prospective trials.