HOCM was primarily diagnosed 18 months before admission to our hospital due to deteriorating symptoms of dyspnea. During that time, intraventricular pressure gradient was 65 mmHg at rest. Due to suspicion of an additional subvalvular membrane she was sent to surgery for myectomy and extirpation of the membrane. Surgery was performed without hemodynamic and clinical success.
Family history was negative regarding HCM and sudden cardiac death. Risk factor stratification showed flat increase of blood pressure during stress test with increase from 110/70 mmHg at rest to 120/60 mmHg at 70 Watts, pre-syncopal attacks, but no NSVT at holter-monitoring and maximal left ventricular wall thickness of 20 mm.
Physical examination showed a mildly overweight 49 year old woman (height 1.63 m, weight 70 kg, BMI 26.4 kg/m2) with a 3/6 typical systolic murmur at 5L2 with increase at Valsalva’s manoeuvre.
ECG at admission (Fig. 1) showed sinus rhythm without signs of LV hypertrophy and no LBBB after surgical myectomy.
Transthoracic echo (Fig. 2) showed typical HOCM with maximal septal thickness of 20 mm, SAM III° with resting gradient of 75 mmHg and provocable gradient of 125 mmHg. Obstruction was also detectable at the level of the papillary muscle. Mild to moderate mitral regurgitation was present - SAM associated and posteriorly directed. At TTE and TEE no subvalvular membrane could be identified.
Holter monitoring showed permanent sinus rhythm with 67 -117 beats / minute and no supraventricular or ventricular tachycardia. Cardiopulmonary exercise testing on a bicycle was performed and the patient reached 72 Watts after 8 minutes. Maximal oxygen uptake (peak VO2) was reduced to 16.6 ml/kg/min (66% predicted peak VO2).
What is your therapeutic strategy?
The resolution of the clinical case
A 49 year-old woman was admitted to our hospital for further evaluation and treatment stratification. At the time of hospitalization she suffered from changing dyspnea class III – IV with symptoms at rest. Clinical symptoms deteriorated typically after meals and after standing up. Furthermore, she reported on angina at mild exertion and sometimes at rest, pre-syncopal attacks independent from exercise, palpitations, and attacks of irregular heart beats. Medication at admission was 120 mg Verapamil twice per day.
Gradient reduction for symptomatic treatment
Therapeutic options for gradient reduction and symptomatic improvement are medical treatment (in Germany betablocker and verapamil), surgical myectomy and septal ablation (PTSMA). In the case, surgical myectomy and additional verapamil medication did not result in effective gradient reduction. Due to the severe clinical symptoms we discussed the alternative treatment options of gradient reduction. Finally, percutaneous septal ablation were performed with hemodynamic good result (Fig. 1 and 2). An AV-block III° was induced. Due to the facts that total heart block persisted and 2 weak risk factors of sudden cardiac death existed we implanted a two chamber ICD
Clinical and echocardiographic follow-up
Clinical follow-up for 5 years after PTSMA is uneventful. The patient reported on an ongoing improvement of symptoms of functional class I-II which is mainly due to diastolic dysfunction. Angina pectoris and syncopal attacks disappeared. Echocardiographic follow-up studies (Fig. 3a and 3b) showed a typical septal thinning and ongoing gradient elimination at rest and provocation. Actual daily medication is 5 mg bisoprolol and 8 mg valsartan.
In this case we could demonstrate that myectomy and PTSMA are complementary treatment options for gradient reduction in HOCM. Surgical myectomy which was performed in addition to extirpation of a subvalvular membrane failed to reduce intracavitary obstruction. Although this obstruction was detectable at the level of the papillary muscle in addition to typical SAM association echo-guided PTSMA resulted in long-lasting gradient elimination. The observed complete heart block occurs in up to 10% of ablation-alone procedures with an increased probability up to 50% after prior myectomy.
In the last 15 years of experience total heart block with consecutive pacemaker implantation remains the most important complication as hospital mortality could be reduced to nearly 0% in experienced centers with knowledge of the special problems and complexities that can emerge in the postinterventional period. In our own series 750 consecutive patients had been treated without hospital death since February 2001.
Our mission: To reduce the burden of cardiovascular disease
© 2018 European Society of Cardiology. All rights reserved