Pre-assessment

Q1. Which of the following conditions may present with similar symptoms to HCM?

Q2. Using echocardiography and/or cardiovascular magnetic resonance (CMR) imaging, what maximal LV wall thickness is consistent with a clinical diagnosis of HCM in the absence of another identifiable cause of that wall thickness?

Q3. State whether the following statement is true or false.

The strongest determinant of heart failure symptoms in patients with HCM is left ventricular outflow tract (LVOT) obstruction.

Q4. Which of the following is most appropriate as the usual initial treatment for symptomatic heart failure in obstructive HCM?

Q5. Is the following statement true or false?

All HCM patients present with T-wave inversions and pseudo-Q waves during 12-lead electrocardiogram examination.

Patient information

Clinical case adapted from Feldman et al.

• Patient is a man in his early 30s
• Two months prior to admission, the patient was diagnosed with presumed nonobstructive hypertrophic cardiomyopathy based on echocardiogram and cardiac magnetic resonance (CMR) imaging demonstrating a maximal left ventricular wall thickness of 16 mm in the basal anterior ventricular septum
• On admission, patient had a witnessed out of hospital cardiac arrest with fast VT as the observed shockable rhythm and received successful cardiopulmonary resuscitation
• Initial electrocardiogram was significant for right bundle branch block with primary AV block and mild ST-segment depressions in the inferior leads
• Emergent coronary angiogram revealed absence of coronary artery disease
• Prior CMR was reviewed, which confirmed increased ventricular septal wall thickness
• There was subepicardial late gadolinium enhancement (LGE) in the basal and mid‑anteroseptum extending into the right ventricular free wall, and focal transmural enhancement in the inferior wall

Q6. Do the features of the CMR image fit with a diagnosis of nonobstructive HCM?

Patient information

Clinical case adapted from Cotrim et al., 2011

• 28-year-old female with a family history of HCM without sudden death
• Experienced daily exertional symptoms with inclines such as stairs or hills
• Cardiac auscultation in left lateral decubitus and orthostatic position revealed no systolic murmur and her ECG was unremarkable
• Echocardiogram revealed septal hypertrophy of 21 mm, but no systolic anterior motion of the mitral valve and therefore no LV outflow tract gradient
• Treadmill exercise echocardiogram was performed, using symptom-limited Bruce protocol
• Immediately post-exercise in the supine position, patient had normal augmentation of systolic function and evidence of accentuation of the degree of SAM, now with mitral valve-ventricular septal contact resulting in an exercise-induced LV outflow tract gradient of 80 mmHg with associated moderate posteriorly directed mitral regurgitation

Q7. What would consider next in patients management plan? (Select all that apply)

Patient information

A 32-year-old suffers a sudden cardiac death. Post-mortem evaluation identified gross and histologic features consistent with a diagnosis of HCM.

Q8. What do you do next? (Select all that apply)

Patient information

Clinical case using data from: Giafaglione et al.

• Patient is a 16-year-old, previously healthy female
• She presented to her pediatrician with syncope, the onset of which was 6 days prior. Additional symptoms of malaise, fever and fatigue, later progressing to include chest pain and shortness of breath were reported
• The patient had a presyncopal episode with dizziness, vision changes and sweating, followed by a true syncopal episode
• On presentation, she was afebrile with a blood pressure of 93/72 mmHg, pulse rate of 90–100 bpm and respiratory rate of 16.
• The results of the physical examination were largely unremarkable. The patient was tachycardic with normal heart sounds and no murmurs, with lungs that were clear to auscultation bilaterally and an abdominal examination demonstrating no hepatosplenomegaly
• The results of the ECG examination showed normal sinus rhythm with low-voltage QRS complexes and T-wave inversions in inferior and anterior leads
• Laboratory evaluation revealed normal electrolytes, complete blood counts, and inflammatory markers, including erythrocyte sedimentation rate and C-reactive protein
• Transthoracic echocardiogram (TTE) showed mildly depressed left ventricular (LV) function with an ejection fraction (EF) of approximately 50% and striking moderate-to-severe concentric LV hypertrophy (LVH) with an LV diastolic septal and posterior wall thickness of 14 mm without outflow tract obstruction

Q9. Is nonobstructive HCM the most likely diagnosis?

Patient information

Clinical case adapted from Monteiro et al.

• 73-year-old female
• History of hypertension, advanced lung disease due to COPD on home oxygen, and atrial fibrillation
• Diagnosed with obstructive HCM
• Progressively worsening exercise-induced dyspnea and orthopnea (NYHA class III) under optimal medical therapy with calcium channel blocker. She could not tolerate beta-blocker due to her severe lung disease and was not a candidate for disopyramide due to a prolonged QTc interval on her ECG
• TTE revealed asymmetric hypertrophy of the left ventricle, with maximal wall thickness in the basal portion of the ventricular septum (19 mm) with hyperdynamic systolic function (EF 65%)
• Dynamic left ventricle outflow tract obstruction gradient of 70 mmHg at rest (120 mmHg with Valsalva maneuver)
• Systolic anterior movement of the mitral valve with mild mitral regurgitation noted
• CMR imaging confirmed basal ventricular septal hypertrophy of 19 mm without evidence of myocardial fibrosis

Q10. What would be the next best approach in management?