Heart Rhythm Abnormalities Following Acute Verapamil Overdose
- PDF / 701,423 Bytes
- 2 Pages / 595.276 x 790.866 pts Page_size
- 87 Downloads / 189 Views
SCIENTIFIC LETTER
Heart Rhythm Abnormalities Following Acute Verapamil Overdose Utkarsh Kohli 1
&
Stephanie Lam 2 & Hunter Eason 3 & Priti Jani 2
Received: 31 August 2020 / Accepted: 25 September 2020 # Dr. K C Chaudhuri Foundation 2020
To the Editor: A 14-y-old female (76 kg) with a past medical history of depression and Graves’ disease presented to our emergency room with palpitations, 3 h after intentional ingestion of 12 (240 mg each) tablets of extended release verapamil (verapamil ER), an amount which is 6 times higher than the maximum recommended daily dose in adults (480 mg). Her examination was reassuring except for tachycardia (102 beats per min) and hypotension (80/40 mmHg). After initial stabilization, an electrocardiogram was obtained [Fig. 1 (Panel A)]. The palpitations resolved in a few hours and no further hemodynamic instability was noted. Serial electrocardiograms were obtained and are shown in Fig. 1 (Panels B-D). Ca2+ channel blockers (CCB) such as verapamil, block the opening of both activated and inactivated myocardial L-type Ca2+ channels. Verapamil’s effects are more marked in tissues that fire frequently, are less completely polarized at rest, and whose activation depends exclusively on the calcium current, such as the SA and AV nodes, where it slows pacemaker activity, and decreases atrioventricular (AV) nodal conduction [1, 2]. However, in contrast to the inhibitory effects on SA and AV nodes, verapamil enhances junctional pacemaker activity which reflects a verapamil effect rather than toxicity [3–5]. Verapamil also has a negative inotropic effect and therefore decreases myocardial contractility [1, 2].
* Utkarsh Kohli [email protected]; [email protected] 1
Division of Pediatric Cardiology, Department of Pediatrics, Comer Children’s Hospital and the Pritzker School of Medicine of the University of Chicago, Chicago, IL, USA
2
Division of Pediatric Critical Care Medicine, Department of Pediatrics, Comer Children’s Hospital and the Pritzker School of Medicine of the University of Chicago, Chicago, IL, USA
3
Department of Pediatrics, Comer Children’s Hospital and the Pritzker School of Medicine of the University of Chicago, Chicago, IL, USA
After ingestion of verapamil ER, peak serum concentrations are attained in 5–11 h. A predominant initial stimulatory effect on the junction (Fig. 1: Panels A and B) followed by depressant effect on the SA and AV nodes, manifested as sinus bradycardia and Mobitz type 1 s-degree AV block (Panel C) was noted in this patient. Thereafter, as the serum verapamil concentration declined over the next 48 h, progressive shortening of the PR interval with eventual resolution of first-degree heart block (Panel D) was seen. The excretion half-life of verapamil ER is approximately 12 h; therefore, approximately 94% of the drug is expected to be cleared from the body by 48 h. Hospitalization for at least 24 h is recommended for all patients after ingestion of verapamil ER tablets. Gastrointestinal decontamination with activated charcoal is a
Data Loading...
