Arrhythmia
Read Time: 2 mins

74/Safety and tolerability of inpatient and outpatient initiation of disopyramide for obstructive hypertrophic cardiomyopathy in a referral centre for septal reduction

Published Online: October 9th 2012 European Journal of Arrhythmia & Electrophysiology. 2022;8(Suppl. 1):abstr74
Authors: YW Liao (Presenting Author) – Liverpool Heart and Chest Hospital, Liverpool; U Raza – Liverpool Heart and Chest Hospital, Liverpool; RM Cooper – Liverpool Heart and Chest Hospital, Liverpool
Quick Links:
Article
Article Information
Article:

Introduction: Left ventricular outflow tract obstruction (LVOTO) is reported in up to two-thirds of hypertrophic cardiomyopathy (HCM) patients. This can cause symptoms of dyspnoea, chest pain, pre-syncope, and syncope. Disopyramide is a negative inotrope that can reduce the pressure gradient created by LVOTO. Disopyramide has a class 1B recommendation for LVOTO in the European Society of Cardiology HCM guidelines and can be trialled in symptomatic patients before proceeding to more invasive treatment.

Purpose: To evaluate the safety and tolerability of disopyramide initiation in an inpatient and outpatient setting.

Methods: A total of 42 patients with obstructive HCM were started on disopyramide in our centre from 2017 to 2022. From 2017 to 2020, all disopyramide initiation required 2 days’ admission with telemetry monitoring, electrocardiogram three times a day, and inpatient echocardiogram. Patients were started on 100 mg three times a day and uptitrated to 250 mg twice a day by Day 2 if there were no rhythm abnormalities or significant conduction or repolarisation changes on electrocardiogram (ECG). We started outpatient initiation from 2020 with a starting dose of 100 mg three times a day and titrating to 250 mg MR twice a day within 3 weeks. All patients had an ECG on the day of initiation, 1 week post initiation and 2 weeks post initiation.

Results: In our inpatient cohort (n=31), there was no significant change in heart rate (HR 73 ± 1 4 bpm to 71 ± 13 bpm). There was some non-significant delay in conduction when peak disopyramide dose was achieved: PR (168 ± 19 ms to 184 ± 27 ms), QRS (104 ± 21 ms to 113 ± 26 ms). Repolarisation measures were also delayed in a non-significant manner: QT (408 ± 38 ms to 439 ± 39 ms) and corrected QT (445 ± 37 ms to 475 ± 41 ms). No patient had QTc >500 ms.

Our outpatient cohort (n=11) had similar findings with HR (67 ± 17 bpm to 66 ± 15 bpm), PR (175 ± 34 ms to 193 ± 35 ms), QRS (113 ± 25 ms to 117 ± 22 ms), QT (428 ± 57 ms to 453 ± 50 ms), and corrected QT (442 ± 25 ms to 467 ± 22 ms).

A total of 11 patients had side effects following initiation and seven patients (17%) had to discontinue treatment. The most common side effects reported were dry mouth (n=6), constipation (n=7), urinary symptoms (n=3), visual changes (n=4) and pre-syncope (n=1). Prolonged QTc >500msec was seen later in two patients on follow-up.

There was no sudden cardiac death or syncope in our patient cohort. For patients who continued on disopyramide (n=35), there was a decrease in the mean New York Heart Association (NYHA) functional class from 2.06 ± 0.7 to1.35 ± 0.5 on a mean follow-up of 171 days. A total of 20 patients (57%) who continued on disopyramide improved by at least one NYHA class (Figure).

Conclusion: Our data suggest disopyramide is effective in improving symptoms of dyspnoea and is safe in patients with obstructive HCM. 17% of patients stopped disopyramide due to side effects and 5% stop due to QTc >500 ms. 

Further Resources

Share this Article
Related Content In Arrhythmia
  • Copied to clipboard!
    accredited arrow-down-editablearrow-downarrow_leftarrow-right-bluearrow-right-dark-bluearrow-right-greenarrow-right-greyarrow-right-orangearrow-right-whitearrow-right-bluearrow-up-orangeavatarcalendarchevron-down consultant-pathologist-nurseconsultant-pathologistcrosscrossdownloademailexclaimationfeedbackfiltergraph-arrowinterviewslinkmdt_iconmenumore_dots nurse-consultantpadlock patient-advocate-pathologistpatient-consultantpatientperson pharmacist-nurseplay_buttonplay-colour-tmcplay-colourAsset 1podcastprinter scenerysearch share single-doctor social_facebooksocial_googleplussocial_instagramsocial_linkedin_altsocial_linkedin_altsocial_pinterestlogo-twitter-glyph-32social_youtubeshape-star (1)tick-bluetick-orangetick-red tick-whiteticktimetranscriptup-arrowwebinar Sponsored Department Location NEW TMM Corporate Services Icons-07NEW TMM Corporate Services Icons-08NEW TMM Corporate Services Icons-09NEW TMM Corporate Services Icons-10NEW TMM Corporate Services Icons-11NEW TMM Corporate Services Icons-12Salary £ TMM-Corp-Site-Icons-01TMM-Corp-Site-Icons-02TMM-Corp-Site-Icons-03TMM-Corp-Site-Icons-04TMM-Corp-Site-Icons-05TMM-Corp-Site-Icons-06TMM-Corp-Site-Icons-07TMM-Corp-Site-Icons-08TMM-Corp-Site-Icons-09TMM-Corp-Site-Icons-10TMM-Corp-Site-Icons-11TMM-Corp-Site-Icons-12TMM-Corp-Site-Icons-13TMM-Corp-Site-Icons-14TMM-Corp-Site-Icons-15TMM-Corp-Site-Icons-16TMM-Corp-Site-Icons-17TMM-Corp-Site-Icons-18TMM-Corp-Site-Icons-19TMM-Corp-Site-Icons-20TMM-Corp-Site-Icons-21TMM-Corp-Site-Icons-22TMM-Corp-Site-Icons-23TMM-Corp-Site-Icons-24TMM-Corp-Site-Icons-25TMM-Corp-Site-Icons-26TMM-Corp-Site-Icons-27TMM-Corp-Site-Icons-28TMM-Corp-Site-Icons-29TMM-Corp-Site-Icons-30TMM-Corp-Site-Icons-31TMM-Corp-Site-Icons-32TMM-Corp-Site-Icons-33TMM-Corp-Site-Icons-34TMM-Corp-Site-Icons-35TMM-Corp-Site-Icons-36TMM-Corp-Site-Icons-37TMM-Corp-Site-Icons-38TMM-Corp-Site-Icons-39TMM-Corp-Site-Icons-40TMM-Corp-Site-Icons-41TMM-Corp-Site-Icons-42TMM-Corp-Site-Icons-43TMM-Corp-Site-Icons-44TMM-Corp-Site-Icons-45TMM-Corp-Site-Icons-46TMM-Corp-Site-Icons-47TMM-Corp-Site-Icons-48TMM-Corp-Site-Icons-49TMM-Corp-Site-Icons-50TMM-Corp-Site-Icons-51TMM-Corp-Site-Icons-52TMM-Corp-Site-Icons-53TMM-Corp-Site-Icons-54TMM-Corp-Site-Icons-55TMM-Corp-Site-Icons-56TMM-Corp-Site-Icons-57TMM-Corp-Site-Icons-58TMM-Corp-Site-Icons-59TMM-Corp-Site-Icons-60TMM-Corp-Site-Icons-61TMM-Corp-Site-Icons-62TMM-Corp-Site-Icons-63TMM-Corp-Site-Icons-64TMM-Corp-Site-Icons-65TMM-Corp-Site-Icons-66TMM-Corp-Site-Icons-67TMM-Corp-Site-Icons-68TMM-Corp-Site-Icons-69TMM-Corp-Site-Icons-70TMM-Corp-Site-Icons-71TMM-Corp-Site-Icons-72