Surgical cryoablation should be considered in patients with mitral valve prolapse (MVP) undergoing mitral valve surgery who have malignant ventricular arrhythmias or high ventricular ectopy load, as recommended in our article now published online in Heart, Lung and Circulation [1].

Mitral valve prolapse is a relatively common condition with a community incidence of about 2.4% [2]. While it generally has good prognosis, a small subset of patients suffer from malignant arrhythmia and sudden cardiac death. Out of 650 autopsies in young adults who died suddenly, 7% were due to MVP [3].

Ventricular ectopics are common in MVP. In a series of 595 consecutive patients, 43% had >5% and one third had moderate or severe nonsustained ventricular tachycardia [4]. These ectopics mainly arise from one or both papillary muscles and may act as triggers for malignant ventricular arrhythmias. Radiofrequency (RF) ablation is considered for malignant arrhythmia or in MVP patients in whom high ventricular ectopy load causes LV dysfunction. RF ablation of the papillary muscles has a modest success rate and high arrhythmia recurrence rate. Mitral valve surgery by itself does not prevent malignant ventricular arrhythmia.

In Heart, Lung and Circulation, we reported 3 cases of MVP and malignant ventricular arrhythmia who not only had mitral valve surgery but also underwent cryoablation of the papillary muscles at the time of surgery.

Two patients had moderate and one severe mitral regurgitation. All had received shocks from their implanted cardioverter defibrillators (ICDs) and were not controlled with drug therapy. At surgery, encircling cryolesions were placed at the base of the papillary muscles which also targets distal arborisation of the Purkinje system. During a follow up of 3–11 years, all three patients have remained free of both malignant arrhythmia and ICD shocks. Cryoablation of papillary muscles had no detrimental effect on mitral valve function for any patient.

While we had not performed cardiac MRI in any of our patients, we would recommend it to assess areas of myocardial fibrosis which could be targeted by cryoablation. Further, wherever possible, we would now consider mitral valve repair rather than replacement.

References

  1. Vohra J, Morton JB, Morgan J, Tatoulis J. Cryoablation of papillary muscles at surgery for malignant ventricular arrhythmias due to mitral valve prolapse. Heart Lung Circ 2022. Link to online article: Cryoablation of Papillary Muscles at Surgery for Malignant Ventricular Arrhythmias Due to Mitral Valve Prolapse – Heart, Lung and Circulation (heartlungcirc.org).
  2. Levine RA, Hagége AA, Judge DP, Padala M, Dal-Bianco JP, Aikawa E, et al.; Leducq Mitral Transatlantic Network. Mitral valve disease—morphology and mechanisms. Nat Rev Cardiol 2015;12:689–710.
  3. Basso C, Perazzolo Marra M, Rizzo S, De Lazaari M, Giorgi B, Cipriani A, et al. Arrhythmic mitral valve prolapse and sudden cardiac death. Circulation 2015;132:556–66.
  4. Essayagh B, Sabbag A, Antoine C, Benfari G, Yang LT, Maalouf J et al. Presentation and outcome of arrhythmic mitral valve prolapse. J Am Coll Cardiol 2020;76:637-49.

By Jitendra Vohra, Joseph B Morton, John Morgan and James Tatoulis

Cryoablation of Papillary Muscles at Surgery for Malignant Ventricular Arrhythmias Due to Mitral Valve Prolapse