Hypertrophic Cardiomyopathy Treatment & Management

Updated: Jan 05, 2016
  • Author: Sandy N Shah, DO, MBA, FACC, FACP, FACOI; Chief Editor: Henry H Ooi, MD, MRCPI  more...
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Treatment

Approach Considerations

Evaluation usually can be conducted on an outpatient basis. Inpatient studies and surgical treatment also may be necessary. Medical and surgical therapy are used to reduce ventricular contractility or increase ventricular volume, increase ventricular compliance and outflow tract dimensions, and, in the case of obstructive hypertrophic cardiomyopathy (HCM), reduce the pressure gradient across the LV outflow tract. Paramount to any therapy is reduction in the risk of sudden death by identification of these patients early on and effective medical and/or surgical implantation of an automatic defibrillator. [18]

Medications include beta blockers, calcium channel blockers, and, rarely, diltiazem, amiodarone, and disopyramide. [19] Antitussives may be administered as needed to avoid coughing.

Research shows that stepwise therapy can reduce high blood pressure in patients with HCM. In a study of 115 HCM patients, including 94 with obstructive HCM, stepwise antihypertensive therapy effectively controlled both obstructive HCM symptoms and hypertension. Average systolic pressure in the obstructive HCM group was reduced from 137 to 131 mm Hg, and uncontrolled hypertension was reduced from 56% at the first visit to 37% at the last. [20, 21]

Avoid inotropic drugs if possible; also avoid nitrates and sympathomimetic amines, except in those patients with concomitant coronary artery disease. Avoid digitalis, because glycosides are contraindicated except in patients with uncontrolled atrial fibrillation. Cautious use of diuretics should be exercised because of their potential adverse effect on the LV outflow gradient and ventricular volume.

American College of Cardiology Foundation/American Heart Association, Heart Rhythm Society, and European Society of Cardiology guidelines

The 2011 ACCF/AHA guidelines [22, 23] and the 2014 ESC guidelines [24] for the diagnosis and treatment of HCM are available here and here, respectively; and the 2012 ACCF/AHA/HRS focused update of the 2008 guidelines for device-based therapy of cardiac rhythm abnormalities [25] is available here.

Transfer

Transfer may be required for further diagnostic evaluation and electrophysiologic device or surgical intervention.

Deterrence/prevention

Patients must abstain from highly strenuous competitive athletic activity and highly strenuous physical exertion, such as shoveling snow or lifting very heavy objects, due to the high risk of arrhythmogenic sudden cardiac death. No acceptable medical recommendation deviates from total abstinence from these activities.

Consultations

Consultations may be indicated with the following specialists:

  • Cardiologist
  • Cardiothoracic surgeon
  • Cardiac electrophysiologist
  • Geneticist

Diet

No special diet is required. However, the patient should avoid excessive weight gain.

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Invasive Therapies

2011 ACCF/AHA recommendations

The 2011 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guidelines recommendations regarding invasive therapies in patients with hypertrophic cardiomyopathy (HCM) are summarized below. [22, 23]

Class I recommendations

Only experienced operators should perform septal reduction therapy, in the setting of a dedicated HCM. Moreover, septal reduction therapy should be reserved for treatment-eligible patients with severe drug-refractory symptoms and left ventricular outlet tract (LVOT) obstruction. (Level of evidence: C)

Class IIa recommendations

It is reasonable to consult with centers experienced in performing surgical septal myectomy and alcohol septal ablation for treatment-eligible patients with HCM with severe drug-refractory symptoms and LVOT obstruction. At these centers, surgical septal myomectomy may be of benefit in symptomatic pediatric patients in whom traditional medical therapy has been ineffective. (Level of evidence: C)

Surgical septal myectomy performed in experienced centers is the first-line option for most treatment-eligible patients with HCM and severe drug-refractory symptoms and LVOT obstruction. Moreover, at these centers, adult patients with HCM and severe drug-refractory symptoms and LVOT obstruction who are not surgical candidates but who are eligible for alcohol septal ablation may benefit from this procedure (usually New York Heart Association [NYHA] class III or IV). (Level of evidence: B)

Class IIb recommendations

In experienced centers, following a detailed discussion with eligible adult patients with HCM and severe drug-refractory symptoms and LVOT obstruction, alcohol septal ablation may be a treatment option to surgical myectomy when the patient indicates a preference for septal ablation. (Level of evidence: B)

In general, alcohol septal ablation is discouraged in patients with HCM and marked (ie, >30 mm) septal hypertrophy owing to uncertainty regarding its efficacy in these patients. (Level of evidence: C)

Precautions (class III recommendations)

Note the following to prevent harm to patients with HCM (C level of evidence for all) [22, 23] :

  • Septal reduction therapy should only be performed as part of a dedicated HCM program.
  • Avoid septal reduction therapy in asymptomatic adults with HCM who have normal exercise tolerance or whose symptoms are controlled/minimized on medical therapy.
  • When septal reduction therapy is a feasible treatment option to relieve LVOT obstruction in eligible patients, do not perform mitral valve replacement as an alternative therapy.
  • Avoid performing alcohol septal ablation in (1) patients with HCM and comorbid conditions that also require surgical repair, in whom myectomy can be performed concomitantly; (2) pediatric patients with HCM (age <21 years); and (3) adults younger than 40 years in whom myectomy is a feasible alternative therapy.
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Left Ventricular Myomectomy and Mitral Valve Replacement

Left ventricular myomectomy

Left ventricular (LV) myomectomy is used for patients with severe symptoms refractory to therapy and an outflow gradient of more than 50 mm Hg, either with provocation or with rest. The procedure typically is successful in abolishing the outflow gradient; most patients have symptomatic improvement for at least 5 years.

The reduction in LV outflow gradient may not correlate with a risk reduction for sudden death or overall mortality. Furthermore, the outflow gradient may increase gradually over time and return to the same level as before, requiring a repeat procedure or additional medical therapy.

Patients who have obstructive hypertrophic cardiomyopathy with low resting gradients and latent obstruction may have limiting symptoms similar to patients with more severe resting gradients. In a series of 749 patients undergoing septal myectomy, 249 had minimal gradients at rest but severe outflow tract obstruction with provocation testing. Symptom relief and survival in these patients was similar to that of patients with severe resting outflow obstruction undergoing myectomy. The authors suggest that septal myectomy may be recommended to patients who have severe outflow obstruction only on provocative testing because survival and symptom relief are excellent, suggesting that dynamic obstruction is the major hemodynamic problem and not diastolic dysfunction. [26]

In a retrospective study (1998-2010) that evaluated data from the Nationwide Inpatient Sample regarding the results of ventricular septal myectomy in patients iwth HCM with refractory LVOT obstruction, Panaich et al found an overall mortality of 5.9%; there was an association between age and severity of comorbidities with higher rates of complications and mortality. [27]

In a prospective observational study (1991-2012) that evaluated the long-term outcomes (8.3 ± 6.1 y) of myectomy combined with anterior mitral leaflet extension in severely symptomatic patients with HCM, Vriesendorp et al reported no operative mortality, with symptomatic relief similar to the general population. [28] Cumulative survival rates at 1 year were 98%; 5 years, 92%; 10 years, 86%; and 15 years, 83%. [28]

In a more recent systematic review and meta-analysis of 10 studies comprising 1824 patients for evaluating the efficacy and short- and long-term mortality of surgical myectomy (n = 1019) compared with alcohol septal ablation (n = 805}, Singh et al found no significant difference in symptomatic relief between the two procedures, and outocomes were similar for sudden cardiac death and short- and long-term mortality. [29]

Mitral valve replacement

Mitral valve replacement is reserved for patients with severe mitral regurgitation due to systolic anterior movement of the mitral valve, particularly when mitral regurgitation (large regurgitant fraction) is associated with the development of congestive heart failure or severe pulmonary hypertension.

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Pacemaker Implantation

Pacemaker implantation has been a proposed treatment for patients with hypertrophic cardiomyopathy (HCM). Studies have shown that pacing the right ventricular RV apex to maintain atrioventricular synchrony results in a decrease of the left ventricular outflow tract (LVOT) gradient, with symptomatic and quality-of-life improvements. [22, 23] A Cochrane review suggested that the benefits of pacing are based on physiologic measures and lacks clinically relevant end-points. [30]

2011 ACCF/AHA recommendations

The 2011 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guidelines recommendations regarding pacing in patients with HCM are summarized below. [22, 23]

Class IIa recommendation

For patients with HCM who previously underwent dual-chamber device implantation for non–HCM-related causes, the ACCF/AHA believe a trial of dual-chamber atrial-ventricular pacing (from the right ventricular apex) for symptomatic relief from LVOT obstruction can be considered. (Level of evidence: B)

Class IIb recommendation

Permanent pacing is an option in symptomatic patients with medically refractory obstructive HCM who are not good candidates for septal reduction therapy. (Level of evidence: B)

Select patients in whom permanent pacemaker implantation is of no benefit (class III recommendations)

The 2011 ACCF/AHA guidelines indicate pacemaker implantation is not beneficial in the following scenarios for patients with HCM [22, 23] :

  • For reduction of the gradient in those who are asymptomatic or whose symptoms are medically-controlled (Level of evidence: C)
  • For first-line treatment of symptomatic relief in candidates eligible for septal reduction who have medically refractory disease and LVOT obstruction (Level of evidence: B)
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Catheter Septal Ablation

Transvenous catheter ablation of the septal region has been performed using selective arterial ethanol infusion to destroy myocardial tissue. [31] The procedure involves infusing 96% ethanol down the first septal branch of the left anterior descending artery and inducing a therapeutic infarction of the proximal interventricular septal myocardium.

This leads to a remodeling of the septum, which decreases the marked septal thickening characteristic of hypertrophic cardiomyopathy (HCM) and results in a decrease of the gradient across the left ventricular outflow tract (LVOT). In this manner, the procedure is analogous to a surgical myomectomy, in attempting to decrease the amount of septal ventricular myocardium and thereby reducing the LVOT gradient.

The procedure has been used in clinical practice since the early 1990s and the reported results have been excellent, with significant reduction in symptoms, particularly in the incidence of heart failure. [32, 33] In many centers, it is the surgical procedure of choice for HCM.

Alcohol septal ablation

Alcohol septal ablation offers some advantages over surgical myectomy in that (1) it does not require surgical incision and/or general anesthesia, (2) the recovery time is shorter, and (3) its results lead to less discomfort and greater patient satisfaction than are reported with surgical myectomy. [22, 23] In addition, older patients who often have multiple comorbidities may better tolerate alcohol septal ablation than septal myectomy, which has high postoperative risks and complications in this patient population. Note that alcohol septal ablation is not indicated for the pediatric population. [22, 23]

The 2011 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guidelines recommendations regarding alcohol septal ablation in patients with HCM are summarized below. [22, 23]

Class I recommendations

As discussed earlier, it is reasonable to consult with centers experienced in performing alcohol septal ablation and surgical septal myectomy for treatment-eligible patients with HCM with severe drug-refractory symptoms and LVOT obstruction.

Use transthoracic (TTE) or transesophageal (TTE) echocardiography for intraoperative guidance of alcohol septal ablation (level of evidence: B) and TTE for assessing the outcomes of alcohol septal ablation (or surgical myectomy) in patients with obstruct HCM (level of evidence: C).

Class IIa recommendations

For clinical decision making and evaluation for the feasibility of alcohol septal ablation, use TEE when TTE findings are unclear.

Class IIb recommendations

In experienced centers, following a detailed discussion with eligible adult patients with HCM and severe drug-refractory symptoms and LVOT obstruction, alcohol septal ablation may be a treatment option to surgical myectomy when the patient indicates a preference for septal ablation. (Level of evidence: B)

In general, alcohol septal ablation is discouraged in patients with HCM and marked (ie, >30 mm) septal hypertrophy owing to uncertainty regarding its efficacy in these patients. (Level of evidence: C)

Class III recommendations

To prevent harm, avoid performing alcohol septal ablation in (1) patients with HCM and comorbid conditions that also require surgical repair, in whom myectomy can be performed concomitantly; (2) pediatric patients with HCM (age <21 years); and (3) adults younger than 40 years in whom myectomy is a feasible alternative therapy. (Level of evidence: C)

Complications of alcohol septal ablation and comparison to surgical myectomy

The European Society of Cardiology (ESC) indicates that the main nonfatal complication of alcohol septal ablation is atrioventricular block (7-20%); in addition, it is associated with 4-5–fold increased risk for permanent pacemaker, as well as right rather than left bundle branch block, compared to septal myectomy. [14] Moreover, although clinical and hemodynamic effects are seen immediately after setpal myectomy, they may be delayed for up to 3 months following alcohol septal ablation.

There appears to be little benefit to alcohol septal ablation in patients whose septal thickness is 30 mm or more (ie, severe HCM), as compared to septal myectomy. [14] The septal myectomy treatment approach visually assesses the anatomy of the LVOT and the mitral apparatus, whereas the alcohol septal ablation approach indirectly ablates the septal perforator artery distribution.

Overall, the procedural mortality for both procedures are similar. [14]

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Implantable Cardioverter Defibrillator

Sudden cardiac death occurs in approximately 1% of patients with hypertrophic cardiomyopathy (HCM) each year, and pharmacotherapy has not shown protection against sudden cardiac death. [22, 23] However, high-risk individuals in whom prophylactic therapy may be indicated may potentially benefit from placement of an implantable cardioverter defibrillator (ICD), which can effectively terminate life-threatening ventricular tachyarrhythmias in the setting of HCM. [22, 23]

2011 ACCF/AHA recommendations

The 2011 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guidelines recommendations regarding ICD placement in patients with HCM are summarized below. [22, 23]

Class I recommendations

ICD placement decision making in patients with HCM should involve a comprehensive discussion between clinicians and patients. (Level of evidence: C)

This procedure is recommended for patients with HCM who have documentation of having suffered cardiac arrest, ventricular fibrillation, or hemodynamically significant VT. (Level of evidence: B)

Class IIa recommendations

ICD placement is a reasonable intervention for patients with HCM who also have (1) one or more first-degree relatives who suffered sudden cardiac death likely related to HCM, (2) an LV wall thickness of 30 mm or more, and (3) one or more recent unexplained syncopal events, as well as for (4) high-risk pediatric patients with HCM and a history of unexplained syncope or massive LV hypertrophy, or a family history of sudden cardiac death, with consideration of long-term ICD complication rates. (Level of evidence: C)

ICD placement is an option for select patients with other risk factors for other sudden cardiac death in addition to having (1) nonsustained VT (eg, age <30 y) or (2) HCM plus exercise-induced blood pressure anomalies. (Level of evidence: C)

For ICD-eligible patients with HCM, it is reasonable to place a single-chamber device in younger patients who do not require atrial or ventricular pacing, or a dual-chamber device (1) in patients with sinus bradycardia and/or paroxysmal atrial fibrillation or (2) predominantly in older patients with high resting outflow gradients (>50 mm Hg) and significant heart failure symptoms in whom right ventricular pacing has the potential beneficial effects. (Level of evidence: C)

Class IIb recommendations

ICD effectiveness remains unclear in patients with HCM who do not have other risk factors for sudden cardiac death but do have either (1) isolated bursts of nonsustained VT or (2) exercise-induced blood pressure anomalies, especially in the setting of significant LVOT. (Level of evidence: C)

Precautions (class III recommendations)

To prevent harm to patients with HCM, do not use ICD placement as either (1) a routine strategy in the absence of high-risk factors or (2) a strategy to allow participation in competitive athletic events. Do not place an ICD in those with a known HCM genotype but who are asymptomatic. (Level of evidence: C)

Complications associated with ICD in HCM

There is a 4% reported rate of ICD-associated complications (procedural and over the long term) per year. [22, 23, 34]  Early complications include the possibility of pneumothorax, pericardial effusion, pocket hematoma, acute pocket infection, and/or lead dislodgment. Complications that may arise late include upper extremity deep venous thrombosis, lead dislodgment, infection, a high defibrillation threshold that may require revision of the the lead, and receipt of inappropriate shocks. [22, 23, 34]

Pediatric patients appear to suffer a higher rate of inappropriate shocks and lead fractures than adults adults do, predominantly owing to the strain placed on the leads as the children grow and are active. [22, 23, 34]

Although the procedure to place ICDs is generally safe, defective generators have been known to cause death, high-voltage leads with small diameters have a tendency to fracture, and patients with severe hypertrophy or who are receiving amiodarone may need high-energy output generators or epicardial lead systems. [22, 23, 34]

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Indications for Heart Transplantation

Heart transplantation is recommended in specific situations for patients with hypertrophic cardiomyopathy (HCM). The 2011 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guidelines indications for heart transplantation include advanced heart disease and New York Heart Association (NYHA) functional class III or IV symptoms that are refractory to all other interventions. [22, 23] In addition, transplant referral for refractory symptoms does not require a reduced ejection fraction (EF), and heart transplantation is performed in the presence of preserved EF. [22, 23]

HCM patient outcome after heart transplant is not different from that of other patients with other heart diseases. [22, 23]

2011 ACCF/AHA recommendations

The 2011 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guidelines recommendations regarding heart transplantation in patients with HCM are summarized below. [22, 23]

Class I recommendations

Heart transplantion should not be considered in the setting of advanced heart failure (end stage) and nonobstructive HCM not otherwise amenable to other treatment intervention, in the presence of an ejection fraction (EF)  that is at or below 50% (or, occasionally, with preserved EF). (Level of evidence: B)

Pediatric heart transplant candidates include those with symptomatic HCM with a restrictive physiology who are not responsive to or appropriate candidates for other therapeutic interventions. (Level of evidence: C)

Precautions (class III recommendations)

To prevent harm, do not perform heart transplantation in mildy symptomatic patients of any age with HCM. (Level of evidence: C)

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Atrial Fibrillation Management

Atrial fibrillation is an important complication of hypertrophic cardiomyopathy (HCM) that is diagnosed by electrocardiography (ECG) during an atrial fibrillation episode, on ambulatory Holter monitoring, or on an event monitor. [22, 23] This arrhythmia generally seen in patients with HCM who are older than 30 years. In addition to increasing age, risk factors for atrial fibrillation in the setting of HCM include congestive heart failure, left atrial function, diameter, and volume. Although patients with HCM and atrial fibrillation may be asymptomatic, there is an increased risk of heart failure, death, and stroke in this population. [22, 23]

2011 ACCF/AHA recommendations

Treatment for atrial fibrillation include symptom control and stroke prevention. The 2011 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guidelines recommendations regarding management of atrial fibrillation in patients with HCM are summarized below. [22, 23]

Class I recommendations

Use vitamin K antagonis (ie, warfarin, to an international normalized ratio [INR] of 2-3) for anticoagulation in patients with paroxysmal, persistent, or chronic atrial fibrillation AF and HCM. (Data are not available in the setting of HCM for anticoagulation with direct thrombin inhibitors such as dabigatran in reducing the risk of thromboembolism). (Level of evidence: C)

Control the ventricular rate in patients with HCM and atrial fibrillation who have rapid ventricular rates. High doses of beta antagonists and nondihydropyridine calcium channel blockers may need to be administered. (Level of evidence: C)

Class IIa recommendations

The ACCF/AHA indicates it is reasonable to use disopyramide (with ventricular rate–controlling agents) and amiodarone for atrial fibrillation in patients with HCM. (Level of evidence: B)

Radiofrequency ablation can be beneficial in the setting of HCM with refractory atrial fibrillation or patients unable to take antiarrhythmic agents. (Level of evidence: B)

Maze procedure with closure of the left atrial appendage is a reasonable intervention in patients with HCM and a histroy of atrial fibrillation. The procedure may be performed during septal myectomy or as an isolated procedure in selected patients. (Level of evidence: C)

Class IIb recommendations

Alternative antiarrhthmic agents for patients with HCM and atrial fibrillation include sotalol, dofetilide, and dronedarone, particularly in those with an implantable cardioverter defibrillator. (Level of evidence: C)

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Pregnacy and Delivery Considerations

In general, women with HCM can safely undergo pregnancy and labor with minimal risks. [22, 23] However, preconception genetic counseling is advised, and it is essential that the expectant mothers receive careful prepregnancy and pregnancy evaluation and functional assessment. Cesarean delivery is usually not required. [22, 23]

If the patient's HCM is controlled with medical therapy, then such management should be continued with careful maternal-fetal monitoring. In setting of advanced disease (eg, progressive heart failure, severe diastolic dysfunction, ventricular tachycardia, supraventricular tachycardia, marked left ventricular outflow tract obstruction [LVOT]), management with a multidisciplinary team that includes a materal-fetal specialist and cardiologist is crucial. [22, 23]

Pillarisetti et al reported that predictors of improvement in left ventricular dysfunction in patients with peripartum cardiomyopathy appear to include postpartum diagnosis and white/Hispanic race. [35]

Data spanning 2 decades and 160,000 deliveries from an institutional review of pregnant women with hypertrophic cardiomyopathy showed a small number of completed pregnancies (23 completed in 14 patients) and no maternofetal deaths. [36] The overall morbidity was 26%, with a 13% incidence of peripartum congestive heart failure. [36]

2011 ACCF/AHA recommendations

The 2011 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) guidelines recommendations regarding management of pregnancy and/or delivery in women with HCM are summarized below. [22, 23]

Class I recommendations

Pregnancy is not contraindicated in asymptomatic women with HCM; perform a careful evaluation for pregnancy risks. Asymptomatic women or those whose symptoms are controlled with beta-blocking drugs should continue pharmacotherapy during their pregnancy, and close monitoring for fetal bradycardia or other complications is important. (Level of evidence: C)

Male and female patients with HCM should receive genetic counseling before planned conception. (Level of evidence: C)

Management by a high-risk obstetric team is essential for women with HCM and resting or provocable LVOT obstruction of 50 mm Hg or greater and/or cardic symptoms not controlled by medical therapy alone. (Level of evidence: C)

Class IIa recommendations

Management by an expert materal-fetal team is advised for women with HCM whose symptoms are controlled (mild to moderate). Such specialist care includes cardiovascular and prenatal monitoring. (Level of evidence: C)

Precautions (class III recommendations)

Women with advanced heart failure symptoms and HCM have an increased risk of  excess morbidity/mortality in pregnancy. (Level of evidence: C)

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Occupational Considerations

Federal Motor Carrier Safety Administration recommendations

The Federal Motor Carrier Safety Administration (FMCSA) sets medical standards and guidelines for commerical motor vehicle drivers. Current guidelines state that individuals with hypertrophic cardiomyopathy (HCM) should not be certified to drive CMV. However, the Medical Expert Panel (MEP) recommends that the guidelines be changed to reflect the fact that not all individuals with HCM are at risk for sudden incapacitation or death. Specifically, the panel recommends that individuals who meet all the following criteria are at low risk and may be certified to drive [37] :

  • No history of cardiac arrest
  • No spontaneous sustained ventricular tachycardia (VT)
  • Normal exercise blood pressure (BP) (eg, no decrease in BP at maximal exercise)
  • No nonsustained VT
  • No family history or premature sudden death
  • No syncope
  • Has an left ventricular (LV) septum thickness of less than 30 mm

However, low-risk individuals must be closely monitored for changes in their risk status. [37]

Federal Aviation Administration standards

The Federal Aviation Administration (FAA) sets the criteria for aircraft pilots with medical conditions, including cardiovascular diseases. [38] Currently, HCM is incompatible with the highest grade aviation license for commercial pilots due to its unpredictable risk for impairment in the cockpit. [39, 40, 41]

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Activity

Avoid strenuous exercise. Competitive-level sports should not be permitted if any of the following is present:

  • Significant outflow gradient
  • Significant ventricular or supraventricular arrhythmia
  • Marked LV hypertrophy
  • History of sudden death in relatives with hypertrophic cardiomyopathy (HCM)
  • Identified malignant genotype
  • Young age (< 30 years)
  • Abnormal blood pressure response to exercise
  • History of syncope, particularly in children

Although avoidance of intense physical exertion is probably appropriate, participation in noncompetitive-level recreational sports activities is not believed to be contraindicated.

Cardiovascular screening before participation in competitive sports appears to reduce the frequency of unexpected sudden death from HCM, although whether large-scale screening of athletes is administratively feasible or cost-effective remains to be determined. [42, 43]

Sudden death often occurs during exercise, but it also demonstrates a circadian distribution, with clustering of deaths in the morning and early evening.

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