Electrocardiographic abnormalities in patients with cluster headache on verapamil therapy
Anna S Cohen1, Manjit S Matharu, Peter J Goadsby
1Headache Group, Institute of Neurology, The National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.
Insights
High-dose verapamil for cluster headache (CH) can cause arrhythmias in 19% of patients and bradycardia in 36%. Electrocardiogram (EKG) monitoring is crucial for patients with CH on verapamil to detect potential heart blocks and bradycardia.
Area of Science:
- Cardiology
- Neurology
Background:
- High-dose verapamil is a common preventive treatment for cluster headache (CH).
- Potential side effects include atrioventricular block and bradycardia, but their incidence in CH patients is not well-established.
Purpose of the Study:
- To assess the incidence of arrhythmias in cluster headache patients receiving high-dose verapamil.
- To determine the frequency of bradycardia and other cardiac side effects.
Main Methods:
- An audit study evaluated 217 outpatients with cluster headache treated with verapamil.
- Doses ranged from 240 mg to 960 mg daily (one patient received 1200 mg/day), with EKGs performed at intervals.
- Arrhythmia incidence was analyzed based on available EKG data.
Main Results:
- Of 108 patients with EKG records, 19% experienced arrhythmias, including first-degree heart block (12%), junctional rhythm, and second-degree heart block.
- Bradycardia (heart rate < 60 bpm) occurred in 36% of patients, though verapamil was discontinued in only 4.
- One patient required a permanent pacemaker due to heart block.
Conclusions:
- Routine EKG monitoring is strongly recommended for all cluster headache patients on verapamil.
- Monitoring helps detect the development of atrioventricular block and symptomatic bradycardia.
- Early detection facilitates timely intervention and management of potential cardiac complications.
Background:
High dose verapamil is an increasingly common preventive treatment in cluster headache (CH). Side effects include atrioventricular block and bradycardia, although their incidence in this population is not clear.
Method:
This audit study assessed the incidence of arrhythmias on high dose verapamil in patients with cluster headache.
Results:
Of three hundred sixty-nine patients with cluster headache, 217 outpatients (175 men) received verapamil, starting at 240 mg daily and increasing by 80 mg every 2 weeks with a check electrocardiogram (EKG), until the CH was suppressed, side effects intervened, or to a maximum daily dose of 960 mg. One patient had 1,200 mg/day. Eighty-nine patients (41%) had no EKGs. One hundred eight had EKGs in the hospital notes, and a further 20 had EKGs done elsewhere. Twenty-one of 108 patients (19%) had arrhythmias. Thirteen (12%) had first-degree heart block (PR > 0.2 s), at 240 to 960 mg/day, with one requiring a permanent pacemaker. Four patients had junctional rhythm, and one had second-degree heart block. Four patients had right bundle branch block. There was bradycardia (HR < 60 bpm) in 39 patients (36%), but verapamil was stopped in only 4 patients. In eight patients the PR interval was lengthened, but not to >0.2 s. The incidence of arrhythmias on verapamil in this patient group is 19%, and bradycardia 36%.
Conclusion:
We therefore strongly recommend EKG monitoring in all patients with cluster headache on verapamil, to observe for the potential development of atrioventricular block and symptomatic bradycardia.
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