HYPERTROPHIC CARDIOMYOPATHY-A CAUSE OF SUDDEN DEATH

-A CASE REPORT

Dr. DEBARSHEE CHAKRABORTY POST GRADUATE TRAINEE,

DEPARTMENT OF FORENSIC MEDICINE AND TOXICOLOGY, GAUHATI MEDICAL

COLLEGE, GUWAHATI.

Dr. RITURAJ CHALIHA PROFESSOR AND HEAD , DEPARTMENT

OF FORENSIC MEDICINE AND TOXICOLOGY, GAUHATI MEDICAL

COLLEGE, GUWAHATI

• Hypertrophic cardiomyopathy (HCM) is a primary disease of the

myocardium (the muscle of the heart) in which a portion of the myocardiumis hypertrophied (thickened) without any obvious cause . It is a leadingcause of sudden cardiac death in young athletes. Younger people are likely tohave a more severe form of hypertrophic cardiomyopathy.

• HCM is frequently asymptomatic until sudden cardiac death, and for thisreason some suggest routinely screening certain populations for this disease.

• A cardiomyopathy is a disease that affects the muscle of the heart. With HCM,the myocytes (cardiac contractile cells) in the heart increase in size, whichresults in the thickening of the heart muscle. In addition, the normalalignment of muscle cells is disrupted, a phenomenon known as myocardialdisarray.

• HCM also causes disruptions of the electrical functions of the heart.

• HCM was initially described by Teare in 1958 • Found massive hypertrophy of ventricular septum in small

cohort of young patients who died suddenly • Braunwald was the first to diagnose HCM clinically in the 1960s • Many names for the disease

Idiopathic hypertrophic subaortic stenosis (IHSS)Muscle subaortic stenosis

Hypertrophic obstructive cardiomyopathy (HOCM)

• Prevalence of HCM: 1:500 to 1:1000 individuals • This occurrence is higher than previously thought, suggesting a

large number of affected but undiagnosed people • Men and African-Americans affected by almost 2:1 ratio over

women and Caucasians • Global disease with most cases reported from USA, Canada,

Western Europe, Israel, & Asia

HCM is most commonly due to amutation in one of 9 sarcomeric genesthat results in a mutated protein in thesarcomere, the primary component ofthe myocyte (the muscle cell of theheart).

These are predominantly single-pointmissense mutations in the genes forbeta-myosin heavy chain (MHC),myosin-binding protein C, cardiactroponinT, or tropomyosin. Thesemutations cause myofibril and myocytestructural abnormalities and possibledeficiencies in force generation.

• Familial hypertrophic cardiomyopathy is inherited as an autosomal dominant trait

• In individuals without a family history of HCM, the most common cause of the disease is a de novo mutation of the gene that produces the β-myosin heavy chain.

• An insertion/deletion polymorphism in the gene encoding for angiotensin converting enzyme (ACE) alters the clinical phenotype of the disease.

• The D/D (deletion/deletion) genotype of ACE is associated with more marked hypertrophy of the left ventricle and may be associated with higher risk of adverse outcome

ASYMTOMATIC

HYPERTROPHIC CARDIOMYOPATHY

MILDLY SYMPTOMATIC

Dyspnea (shortness of breath)

Chest pain (angina)

Palpitations

Lightheadedness, fatigue, fainting (called syncope)

Sudden cardiac death

“jerky” rapidly rising pulse, an apical systolic murmur which increases with the

Valsalva manoeuvre , a fourth heart sound.

ECG) may show abnormalities including voltage criteria for left ventricular

hypertrophy, T-wave inversion and Q waves

Risk Stratification for Sudden Cardiac Death in HCM

Major Risk Factors • Left ventricular wall thickness ≥ 30 mm • Family history of premature sudden cardiac

death • Previous cardiac arrest/ventricular tachycardia • Previous episodes of documented NSVT (≥ 3

beats, rate ≥ 120 bpm) • Unexplained syncope

Other Risk Factors • Abnormal blood pressure response to exercise*

• Evidence of myocardial ischaemia• Left ventricular outflow tract obstruction (≥ 30

mmHg at rest, or with • provocation

* Abnormal blood pressure response to exercise is defined as an increase in systolic BP <20mmHg, no rise, or a fall in BP > 20mmHg during exercise, or a disproportionate fall inblood pressure immediately post-exercise. NSVT = nonsustained ventricular tachycardia,bpm = beats per minute.

• Can be asymmetric• Wall thickness >15 mm

• Left atrium >40 mm

• Left ventricular end diastolic diameter (LVEDD) <45 mm

• Diastolic function – Always abnormal

* Significant amount of infiltration

* Myocardial * Myocardial

Echocardiography, Cardiac catheterizationCardiac MRIECG and genetic testCardiac biopsy

On external examination, thedead body was found to be ofHeavy built and browncomplexion with eyes andmouth closed. No externalinjuries were found.

Rigor mortis was found to be fully developed over whole body and Postmortem hypostasis was present and fixed and Body was cold on touch.

On internal examination, all the organs were found to be congested.

Lungs:

Liver and GB :

Kidney:: Brain:

The heart was found massively enlarged weighing 790 grams.

Left ventricular wall thickness: 4.6 cmRight ventricular wall thickness: 4.1 cmLeft atrial thickness: 2 cmRight atrial thickness: 1.6 cm

12 to 24 hours

Opinion regarding the cause of death has been keptpending till the receipt of Histo-Pathological Examinationreport from the Deptt. Of Pathology GMCH.

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