Hypertrophic Cardiomyopathy

Abstract

Hypertrophic cardiomyopathy (HCM) is a relatively common disorder that anesthesiologists encounter among patients in the perioperative period. Fifty years ago, HCM was thought to be an obscure disease. Today, however, our understanding and ability to diagnose patients with HCM have improved dramatically. Patients with HCM have genotypic and phenotypic variability. Indeed, a subgroup of these patients exhibits the HCM genotype but not the phenotype (left ventricular hypertrophy). There are a number of treatment modalities for these patients, including pharmacotherapy to control symptoms, implantable cardiac defibrillators to manage malignant arrhythmias, and surgical myectomy and septal ablation to decrease the left ventricular outflow obstruction. Accurate diagnosis is vital for the perioperative management of these patients. Diagnosis is most often made using echocardiographic assessment of left ventricular hypertrophy, left ventricular outflow tract gradients, systolic and diastolic function, and mitral valve anatomy and function. Cardiac magnetic resonance imaging also has a diagnostic role by determining the extent and location of left ventricular hypertrophy and the anatomic abnormalities of the mitral valve and papillary muscles. In this review on hypertrophic cardiomyopathy for the noncardiac anesthesiologist, we discuss the clinical presentation and genetic mutations associated with HCM, the critical role of echocardiography in the diagnosis and the assessment of surgical interventions, and the perioperative management of patients with HCM undergoing noncardiac surgery and management of the parturient with HCM.

Role of echocardiography in the diagnosis and management of hypertrophic cardiomyopathy

“…Taking into account the haemodynamic conditions under general anaesthesia during the procedure, isoproterenol administration or premature ventricular contraction (PVC) evaluating post-extraystolic potentiation ( Brockenbrough manoeuvre ) could be considered to assess an adequate resection 36. Gradients >25 mm Hg or post-PVC >50 mm Hg as well as more than mild MR should lead to revision and further resection or MV repair if appropriate 36…”

“…Echocardiography constitutes a useful tool to provide accurate preoperative risk stratification36 and should evaluate:LV systolic function.degree of diastolic dysfunction. LVOT gradient and results of prior interventions.MR and abnormalities of MV and subvalvular apparatus.pulmonary hypertension. …”

Recent Advances in Hypertrophic Cardiomyopathy: A System Review

“…The indications for ICD placement are (1) positive family history of several sudden cardiac deaths in a distant family member, (2) nonsustained ventricular tachycardia on Holter monitoring, (3) LVH >30 mm, (4) prior unexplained syncope during exercise or at rest, and (5) an abnormal blood pressure response during exercise, which can be described as progressive decrease in the systolic value by 20 mm Hg after an initial increase or an increase in systolic blood pressure of <20 mm Hg from the baseline value or a [2,63,64]. The decision for placement of primary prevention of ICD in HCM often involves a large measure of individual clinical judgment, particularly when the evidence for risk is ambiguous.…”

Recent Advances in the Molecular Genetics of Familial Hypertrophic Cardiomyopathy in South Asian Descendants

“…Prototypical cases of HCM show abnormally large and misaligned myocytes localized to the interventricular septum and increased fibrosis (Gersh et al, 2011). The thickened and stiff ventricle reduces the compliance of the heart muscle, decreases preload, and contributes to diastolic heart failure (Jacoby et al, 2013; Hensley et al, 2015). On the other end of the spectrum, typical DCM cases show chamber volume dilatation and thin walls, which reduces contractile force, and causes systolic heart failure.…”

“…The dynamic nature of LVOT obstruction aids in differentiation of HCM from other conditions in which LVH is the result of chronic and fixed pressure overload (Jacoby et al, 2013). LVOT obstruction, as well as other diagnostic hallmarks of HCM, can be detected via non-invasive imaging techniques such as echocardiography and cardiac MRI (Hensley et al, 2015) and in some cases provoked by altering loading conditions of the heart.…”