Page 101 - Migraine, the heart and the brain

Cardiac monitoring of high dose verapamil in cluster headache
introduCtion
Cluster headache is a highly disabling brain disorder characterized by recurrent attacks of intense unilateral headache and facial autonomic features for 30-180 minutes. 1 Attacks typically strike several times a day, in most patients clustered in periods of several weeks to months alternating with attack-free periods of months to years (episodic cluster headache).1 Up to 20% of patients may have chronic cluster headache without attack-free periods. To prevent attacks, treatment guidelines recommend verapamil in doses which usually exceed those generally used in cardiovascular disease.2,3 Adverse events of high dose verapamil (HDV) may include cardiac arrhythmia, heart failure, and pulmonary edema.4 Consequently, patients with AV blocks, ventricular dysfunction, hypotension, or certain forms of atrial brillation are usually excluded.4 Evidence-based guidelines on how to prescreen and monitor cardiac safety in cluster headache patients treated with HDV are, however, lacking.2,5 In clinical practice this may cause sub-optimal treatment results of HDV in some patients.
The goal of the present study was to de ne guidelines for safe use and electrocardiogram (EKG) monitoring of HDV in cluster headache. To this end we 6 interviewed cardiologists who are experts in cardiac rhythm disorders and used the
Delphi approach to arrive at consensus.
methods
We randomly identi ed 40 cardiologists from the membership list of the Heart Rhythm Society who were invited to participate. Cardiologists were eligible if they had been rst or last author of at least ve publications on cardiac rhythm disorders in peer reviewed medical journal in the last 10 years. Twenty-two (55%) responded and completed the questionnaires. (participants see e-table 1)
A case vignette was presented in which a patient with cluster headache and no cardiac medical history was prescribed with verapamil 240 mg/day. We used the Delphi approach6 to arrive at consensus about the EKG protocol and which EKG ndings were considered contraindications for continuation of verapamil. The rst round included questions about possible EKG protocols using a ve point Likert scale. Consensus was de ned as answers ‘strongly agree’ and ‘agree’ added up to ≥ 80%. When no consensus was reached, propositions were taken to the second
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