Author + information
- Cheng Sainan and
- Shihua Zhao
The end-stage hypertrophic cardiomyopathy (ES-HCM) is part of the clinical spectrum of HCM. Systematic evaluation of clinical and magnetic resonance imaging (MRI) characteristics of this spectrum has not been performed. The purpose of this study was to clarify the clinical and MRI characteristics in ES-HCM patients.
We collected 72 ES-HCM patients characterized by systolic dysfunction (left ventricular eject function < 50%). According to the cardiac structure and hemodynamics, ES-HCM patients were divided into those with dilated phenotype (D-ES, n=42) and those with restrictive phenotype (R-ES, n=30). All of the patients underwent MRI.
ES-HCM developed at a wide age range (12 to 70 years), with 35% of patients < 40 years old. The clinical manifestation did not differ significantly between the two groups, including chest distress (41), dyspnea (49), palpitation (20), amaurosis (7), syncope (7) and edema of lower extremity (18). The New York Heart Association functional class≥2 in all patients. The incidence of atrial fibrillation, intraventricular block, nonsustained ventricular tachycardia were 46%, 28%, 18% respectively. The maximum wall thickness were over 15mm in 67 patients. Regional LV wall thickness was decreased in 26 patients (23 in D-ES vs. 3 in R-ES, p < 0.05). The left and right atrial anteroposterior diameter (LAD, RAD) were 47.33mm, 44.67mm in D-ES and 54.57mm, 63.57mm in R-ES. The left and right ventricular short axis diameter were 65.86mm, 31.33mm in D-ES and 48.10mm, 32.40mm in R-ES. There was significant difference between the two groups in LV end diastolic volume (130.77 ml/m2 in D-ES, 61.12 ml/m2 in R-ES, p < 0.05). Late gadolinium enhancement (LGE) demonstrated focal or diffuse LGE at the LV wall in 100% of ES-HCM. LGE volume fraction was significantly larger in D-ES (37.9%) than in R-ES (19.6%) (p < 0.05).
This study demonstrated that patients with end-stage HCM have expanded clinical expression and MRI characteristics, including dilated phenotype and restrictive phenotype. Besides, the D-ES patients had more LGE distributed diffusely throughout ventricular septum and LV free wall than the R-ES patients. MRI has an important application value in the diagnosis and evaluation of ES-HCM.