The concepts underlying hypertrophic cardiomyopathy (HCM) pathogenesis have evolved greatly over the last 60 years since the pioneering work of the British pathologist Donald Teare, presenting the autopsy findings of “asymmetric hypertrophy of the heart in young adults”. Advances in human genome analysis and cardiac imaging techniques have enriched our understanding of the complex architecture of the malady and shaped the way we perceive the illness continuum. Presently, HCM is acknowledged as “a disease of the sarcomere”, where the relationship between genotype and phenotype is not straightforward but subject to various genetic and nongenetic influences. The focus of this review is to discuss key aspects related to molecular mechanisms and imaging aspects that have prompted genotype–phenotype correlations, which will hopefully empower patient-tailored health interventions.
Background: The aim of this study was to explore the rare variants in a cohort of Romanian index cases with hypertrophic cardiomyopathy (HCM). Methods: Forty-five unrelated probands with HCM were screened by targeted next generation sequencing (NGS) of 47 core and emerging genes connected with HCM. Results: We identified 95 variants with allele frequency < 0.1% in population databases. MYBPC3 and TTN had the largest number of rare variants (17 variants each). A definite genetic etiology was found in 6 probands (13.3%), while inconclusive results due to either known or novel variants were established in 31 cases (68.9%). All disease-causing variants were detected in sarcomeric genes (MYBPC3 and MYH7 with two cases each, and one case in TNNI3 and TPM1 respectively). Multiple variants were detected in 27 subjects (60%), but no proband carried more than one causal variant. Of note, almost half of the rare variants were novel. Conclusions: Herein we reported for the first time the rare variants identified in core and putative genes associated with HCM in a cohort of Romanian unrelated adult patients. The clinical significance of most detected variants is yet to be established, additional studies based on segregation analysis being required for definite classification.
Background: Anomalies of the mitral apparatus have been shown to contribute to left ventricular outflow obstruction in patients with hypertrophic cardiomyopathy (HCM). We report our 5-year single-center experience with a shallow myectomy procedure associated with transaortic mitral valve repair in a cohort of HCM patients. Methods: We studied 83 consecutive patients who underwent surgical treatment of symptomatic left ventricular outflow obstruction. In all study patients, a transaortic shallow septal myectomy was performed. Fibrous or muscular structures connecting the papillary muscles to the septum or free wall were resected, and fibrotic secondary chordae of the anterior mitral valve were cut selectively. Results: We report one death (1.2%) during hospitalization, no iatrogenic ventricular septal defects, and two (2.4%) mitral valve replacements. At discharge, no patients were in New York Heart Association (NYHA) Class III/IV, from 49 (59%) preoperatively. Mean maximal septal thickness decreased from 24 ± 6 to 16 ± 3 mm. Mean outflow gradient decreased from 93 ± 33 to 13 ± 11 mmHg. Grade 3 or 4 mitral regurgitation was noticed in one patient postoperatively, from 32 (39%) before surgery. Conclusions: Shallow septal myectomy associated with secondary mitral valve chordal cutting and papillary muscle mobilization provided excellent results offering adequate treatment of outflow obstruction.
3 September 2022 in European Heart Journal - Cardiovascular Imaging
In patients with obstructive hypertrophic cardiomyopathy (HCM) and mild septal thickness undergoing myectomy, resecting fibrotic anterior mitral leaflet (AML) secondary chordae moves the mitral valve (MV) away from the outflow tract and ejection flow, reducing the need for a deep septal excision. Aim of the present study was to assess whether chordal resection has similarly favourable effects in patients with important hypertrophy, who represent the majority of patients with obstructive HCM. The MV position in the ventricular cavity, assessed from echocardiography as AML-annulus ratio, was compared before and after chordal resection in 150 consecutive HCM patients with important (≥20 mm) and 62 with mild (≤19 mm) septal thickness undergoing myectomy. Preoperatively, MV position was displaced towards the septum to a similar extent in both groups. Postoperatively, AML-annulus ratio increased of an equal degree in both groups, from 0.43 ± 0.05 to 0.55 ± 0.06 (P < 0.001) a 28% increase, and from 0.43 ± 0.06 to 0.55 ± 0.06 (P < 0.001) a 26% increase, respectively, indicating a similar MV shift away from the outflow tract. When AML-annulus ratio was compared in the study cohort and 124 normal subjects, MV position was within normal range in 50% postoperatively. In obstructive HCM, displacement of the MV apparatus into the outflow tract interferes with the ejection flow. Resection of fibrotic secondary chordae moves the MV apparatus away from the outflow tract and enlarges the outflow area independently of septal thickness, facilitating septal myectomy by reducing the need for a deep muscular excision.
Introduction The association between both left and right ventricular free wall ruptures (FWR) and post-infarction anterior ventricular septal defect (VSD) is an exceptional situation. Case report We present the case of a patient who developed a VSD and two FWRs (of the left and right ventricle, respectively) shortly after the onset of an anterior AMI. We surgically closed this complex rupture using the cohesive double patch technique with two Teflon patches combined with an infarct exclusion technique. The left and right ventricular patches were attached cohesively to the septal wall and the infarcted area was excluded without reducing the left ventricular cavity. Conclusion Association between post-infarction ventricular septal rupture and both left and right free wall ruptures are a very rare and dangerous situation. The modified cohesive double patch technique associated the modified Cooley technique seems to be the correct surgical solution.
Post-infarction left ventricular aneurysm is an uncommon but severe mechanical complication of transmural myocardial infarction, particularly in patients with delayed presentation or incomplete myocardial salvage. It may lead to profound distortion of left ventricular geometry, adverse remodelling, intraventricular thrombosis, mitral regurgitation, pulmonary hypertension, and advanced heart failure. We report the case of a 65-year-old male patient referred two months after a late-presenting anterior ST-segment elevation myocardial infarction caused by proximal occlusion of the left anterior descending coronary artery. At admission, the patient presented with severe decompensated heart failure, low-output status, multiorgan dysfunction, and a left ventricular ejection fraction of 12%. Transthoracic echocardiography and cardiac magnetic resonance imaging demonstrated a giant apical left ventricular aneurysm involving approximately 75% of the ventricular cavity, partial intraluminal thrombosis, extensive transmural scarring in the left anterior descending territory, and imaging features suggestive of a chronic contained free-wall rupture/pseudoaneurysmal component. Following multidisciplinary evaluation, the patient underwent surgical ventricular reconstruction using an endoventricular circular restoration technique guided by an intraventricular balloon sizer, combined with left internal thoracic artery bypass grafting to the left anterior descending artery. The early postoperative course required temporary inotropic, vasopressor, inhaled nitric oxide, and intra-aortic balloon pump support, followed by progressive haemodynamic recovery. The patient was discharged on postoperative day seven with functional improvement to NYHA class II. At six-month follow-up, he remained clinically stable without overt signs of heart failure, and echocardiography showed preserved ventricular geometry and improvement of left ventricular ejection fraction to 45%. This case highlights the potential role of carefully planned, balloon-guided surgical ventricular reconstruction in selected patients with giant post-infarction left ventricular aneurysms and end-stage heart failure when residual viable myocardium is present.