Case cơ tim phì đại - Nguyễn Thị Mai Ngọc

 Clinical case of syncope in a 
Hypertrophic Cardiomyopathy patient (with 
MHY7 gene mutation) 
Nguyen Thi Mai Ngoc MD, PhD 
Viet Nam National Heart Institute 
Bach Mai General Hospital 
The HCM patient with the MYH7 gene mutation: 
Male of 36 years old. 
Hospitalized with syncope. 
Diagnosed with HCM since 2003. 
Symptoms: chest pain, exertional dyspnea. 
Treated with Tildiazem 120 mg/d. 
Family history: Nobody in first-degree relative with HCM. 
The HCM patient with the MYH7 gene mutation: 
 Physical examination: HR 100 b/min, BP 120/70 mmHg. 
 ECG: normal sinus rhythm. 
 Ambulatory Holter: no cardiac arhythmias. 
 Doppler echocardiography: 
 HCM of asymmetric septal hypertrophy. 
 No evidence of left ventricular outflow obstruction. 
 Mild mitral regurgitation. 
 Cardiac catheterization: 
 No evidence of left ventricular outflow obstruction. 
 Normal coronary arteries. 
The HCM patient with the MYH7 gene mutation: 
 HCM is the most prominent among the genetic heart disease, 
to be about 0,2% (1.e., 1:500) in the general population. 
 HCM is regarded as a disease entity caused by autosomal 
dominant mutations in genes encoding protein components of 
the sarcome and its contituent myofilament elements. 
Prognosis profiles for HCM and targets for therapy 
The HCM patient with the ß myosin heavy chain 7 
(MYH7) gene mutation: 
Genetic testing: MYH7 gene mutation (exon 13, Arg 403 Gln): 
Characteristic & prognosis implication of myosin missense 
mutation in HCM: 
 High risk of sudden death: 
 Mutation Arg403Gln 
 Arg719Trp 
 Arg453Cys. 
 Intermediate risk of premature sudden death: 
 Arg249Gln 
 Glu930Lys 
 Carrier of other MYH7 mutations would normal risk of premature sudden 
death: Gly256Glu, Val606Meth, Leu908Val 
The questions: 
 How to prevent sudden death in patients with HCM? 
 What are the best present treatments for HCM? 
Xin ch©n thµnh c¶m ¬n ! 
2011-2013 
 46 patients were hospitalized and diagnosed with 
Hypertrophic Cardiomyopathy (HCM) 
 Symptoms included: 
 Chest pain (occurs usually with exercise or physical activity) 
 Shortness of breath (dyspnea), especially with exertion 
 Fatigue (feeling overly tired) 
 Fainting (caused by irregular heart rhythms or no cause found) 
 Palpitations. 
Among the 46 HCM patients: 
 21 patients with HCM had the pressure gradient in the left 
ventricular outlet: 
 Age: 16-49 years 
 Gender: Male 62%, Female 38%. 
 The mean pressure gradient in the left ventricular outlet: 
 Max: 141 mmHg. 
 Min: 31 mmHg. 
 > 50 mmHg: 14 pts (67%). 
 Mitral regurgitation: 95% of mild to intermediate MR; 5% with 
 severe MR 
Among the 21 HCM patients with left ventricular outflow 
obstruction: 
 10 patients were genetic tested. 
 But only 1 patient was identified having mutation in the ß 
myosin heavy chain 7 gene (MYH7 gene). 
 The genotype was mutation Arg403Gln 
The mutation Arg403Gln means: 
 At codon position 403 region encoding the globular head 
of protein of a patient with MYH7 gene point mutations 
such as nucleotide Arginine (Arg) is replaced by Glutamine 
(Gln).