Hypertrophic Cardiomyopathy in Saudi Arabia: A Systematic Review of the Epidemiological, Clinical, and Imaging Features.

BACKGROUND: A systematic review was performed to deliver a critical view of clinical and research practice on hypertrophic cardiomyopathy (HCM) in Saudi Arabia. Scopus, PubMed, and Google Scholar databases were searched for original articles reporting clinical and/or imaging findings among HCM patients in Saudi Arabia. Of 559 records identified, 3 studies and 1 abstract were included, involving 169 patients. METHODS: The mean age ranged between 40and 56 years, up to 93.3% were males. A family history of HCM was reported in one study (5%), and sudden cardiac death was investigated in two studies (9% and 13%). Dyspnea was the most frequent symptom (60-68.7%) reported, followed by chest pain (12.5%-73.3%). RESULTS: Regarding complications, atrial fibrillation was reported among 0-25% of the patients, mitral regurgitations among 13.3-50%, and ventricular tachycardia among 5-12.5%. Imaging parameters were inadequately documented and suggested a high prevalence of left atrial enlargement, SVI + RV5 > 35 mm, blocks, and asymmetric septal hypertrophy. CONCLUSION: The ejection fraction was reported by two studies with a mean±SD of 68±13% and 77.2±8.07%. The researchers stress the paucity, low quality, and disparity in time of original studies about HCM in Saudi Arabia and recommend conducting national multicenter studies, with appropriate design, notably using screening-based recruitment methods.

Hypertrophic cardiomyopathy in children.

Hypertrophic cardiomyopathy (HCM) characterized by asymmetric ventricular septal hypertrophy, is the commonest cause of sudden cardiac death (SCD) in the young. The underlying etiology of HCM in the childhood and adolescent patients is diverse. Moreover, the prognosis of pediatric HCM depends on the age of presentation and etiology. Despite the complexity of children with obstructive HCM, surgical treatment results in a favorable outcome for carefully selected patients in experienced tertiary referral center in contemporary era. Implantable cardioverter-defibrillator (ICD) remains the most effective and reliable treatment to prevent SCD. New pediatric SCD risk prediction model, which has good discrimination and calibration and can distinguish patients who are most benefit from an ICD implantation, is expected to be further refined in the future.

A novel nonsense mutation in TNNT2 in a Chinese pedigree with hypertrophic cardiomyopathy: A case report.

RATIONALE: Hypertrophic cardiomyopathy (HCM) is an inherited myocardial disease and a common cause of sudden cardiac death, heart failure, atrial fibrillation and stroke. In families affected by HCM, genotyping is useful for identifying susceptible relatives. In the present study, we investigated the disease-causing mutations in a three-generation Chinese family with HCM using whole exome sequencing (WES). PATIENT CONCERNS: The proband, a 50-year-old man, was diagnosed with HCM at the age of 41 years. He presented with an asymmetric hypertrophic interventricular septum and a maximum interventricular septum thickness of 18.04 mm. His third elder sister, niece and daughter were also clinically affected by HCM. DIAGNOSIS: Autosomal dominant HCM. INTERVENTIONS: Seven family members, including 4 affected members, accepted WES. The genetic variants were subsequently called using Genome Analysis Toolkit and annotated using the InterVar program. Following frequency filtration by the Genome Aggregation Database, the variants were evaluated using an in-house bioinformatics analysis pipeline. OUTCOMES: HCM was transmitted as an autosomal dominant trait in the family. An extremely rare stop gained mutation, rs796925245 (g.1:201359630G>A, c.835C>T, p.Gln279Ter) in the troponin T2 (TNNT2) gene was identified as the disease-causing mutation. The stop gained mutation was predicted to result in a truncated troponin T protein in cardiac sarcomere. An adolescent family member who had normal echocardiographic measurements was found to carry the same disease-causing mutation. LESSONS: A novel nonsense TNNT2 mutation was identified as the HCM-causing mutation in this Chinese pedigree. Since HCM shows a low penetrance by clinical criteria in adolescents, the adolescent mutation carrier, who is still clinically unaffected, should be offered routine follow-ups and sport activity recommendations to prevent adverse events including sudden cardiac death in the future.

Significance of Pulmonary Hypertension in Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is the most prevalent hereditary cardiac disease characterized by the presence of left ventricular and/or septal hypertrophy in the absence of other underlying cardiac disorders. Patients of HCM have a broad range of clinical presentation from being asymptomatic to severely ill condition requires hospitalization and urgent management. Broadly, HCM is classified in two variants: obstructive and nonobstructive. The mainstay of diagnosis is through echocardiography. As HCM chiefly affect the left heart, pulmonary hypertension (PH) is an expected complication of this disease. Though the existence of PH in HCM is known for a long time, its clinical significance, underlying mechanism, and prognostic impact in HCM have been revealed by few recent studies. Specifically, studies have shown increased events of thromboembolism, atrial fibrillation, and heart failure in patients with HCM and PH. These studies elucidated the underlying mechanism of PH in HCM--a rise of pressure in the precapillary and postcapillary pulmonary vasculature. In addition to left ventricular involvement, studies have shown right ventricular involvement and the association of left and right ventricular dysfunction in these patients. Further, it has been shown that surgical intervention to reduce septal thickness improves survival in pharmacotherapy nonresponders and the presence of PH does not increase mortality in these patients. We present a comprehensive review exploring the prevalence, underlying mechanisms, and impact of PH on HCM.

Anterior myocardial infarction in a patient with isolated left ventricular non-compaction.

We presented a 55-year-old male patient with isolated left ventricular non-compaction who was admitted to our emergency department for chest pain and exertional dyspnoea. He was hospitalised due to anterior myocardial infarction, and during his assessment, isolated left ventricular non-compaction was diagnosed.

CaMKII-mediated phosphorylation of RyR2 plays a crucial role in aberrant Ca2+ release as an arrhythmogenic substrate in cardiac troponin T-related familial hypertrophic cardiomyopathy.

AIMS: Cardiac Troponin T (TnT) mutation-linked familial hypertrophic cardiomyopathy (FHC) is known to cause sudden cardiac death at a young age. Here, we investigated the role of the Ca2+ release channel of the cardiac sarcoplasmic reticulum (SR), ryanodine receptor (RyR2), in the pathogenic mechanism of lethal arrhythmia in FHC-related TnT-mutated transgenic mice (TG; TnT-delta160E). METHODS AND RESULTS: In TG cardiomyocytes, the Ca2+ spark frequency (SpF) was much higher than that in non-TG cardiomyocytes. These differences were more pronounced in the presence of isoproterenol (ISO; 10 nM). This increase in SpF was largely reversed by a CaMKII inhibitor (KN-93), but not by a protein kinase A inhibitor (H89). CaMKII phosphorylation at Ser2814 in RyR2 was increased significantly in TG. Spontaneous Ca2+ transients (sCaTs) after cessation of a 1-5 Hz pacing, frequently observed in ISO-treated TG cardiomyocytes, were also attenuated by KN-93, but not by H89. The RyR2 stabilizer dantrolene attenuated Ca2+ sparks and sCaTs in ISO-treated TG cardiomyocytes, indicating that the mutation-linked aberrant Ca2+ release is mediated by destabilized RyR2. CONCLUSIONS: In FHC-linked TnT-mutated hearts, RyR2 is susceptible to CaMKII-mediated phosphorylation, presumably because of a mutation-linked increase in diastolic [Ca2+]i, causing aberrant Ca2+ release leading to lethal arrhythmia.

Familial hypertrophic cardiomyopathy: A case with a new mutation in the MYBPC3 gene.

Familial hypertrophic cardiomyopathy is a genetically heterogeneous disease with variable clinical features that is inherited as autosomal dominant with variable penetrance. Recent developments in genetics of hereditary cardiomyopathy have not only enlightened many points about pathogenesis, but have also provided great benefit to diagnostic approaches of clinicians. Heterozygous mutation of c3691-3692insTTCA in MYBPC3 gene was identified in a pediatric patient with diagnosis of hypertrophic cardiomyopathy at clinic. Hypertrophy was observed in sister and father of the patient in echocardiography screening, and it was subsequently determined that they also had same mutation. This mutation has not previously been defined and reported previously in the literature as cause of hypertrophic cardiomyopathy.

Sudden Collapse of a Preschool-Aged Child on the Playground.

PURPOSE: Primary cardiac events are rare in children. There is little information in the literature regarding the most appropriate emergency department (ED) management of this type of pediatric patient, especially with regard to medication use. SUMMARY: This case highlights the pediatric ED evaluation and treatment of sudden collapse in a child with an ultimate diagnosis of hypertrophic cardiomyopathy. Cardiac disorders represent 2% to 6% of cases of pediatric syncope presenting to EDs, particularly if there are previous prodromal symptoms and/or a history of exertion. Evaluation should include electrocardiogram, chest radiograph, and echocardiogram if available. Management should focus on decreasing the potential for a recurring arrhythmia while maintaining cardiac preload, which can be worsened with certain medication use. CONCLUSIONS: Although primary cardiac events in children are rare, a high index of suspicion should be maintained especially with a history of prodromal symptoms or collapse during exertion. If cardiac etiology is suspected, deliberate management should be used to exclude a treatment that could be detrimental. This case report provides an initial assessment and recommendations for management of these patients.

Left ventricular non-compaction cardiomyopathy: Incidental diagnosis after ST-elevation myocardial infarction.

Left ventricular non-compaction cardiomyopathy is a rare congenital cardiomyopathy, which usually presents early in life but may also manifest into adulthood. We present the case of an elderly woman with left ventricular non-compaction cardiomyopathy, which was discovered incidentally following an ST-elevation myocardial infarction.

Plan of Action for Inherited Cardiovascular Diseases: Synthesis of Recommendations and Action Algorithms.

The term inherited cardiovascular disease encompasses a group of cardiovascular diseases (cardiomyopathies, channelopathies, certain aortic diseases, and other syndromes) with a number of common characteristics: they have a genetic basis, a familial presentation, a heterogeneous clinical course, and, finally, can all be associated with sudden cardiac death. The present document summarizes some important concepts related to recent advances in sequencing techniques and understanding of the genetic bases of these diseases. We propose diagnostic algorithms and clinical practice recommendations and discuss controversial aspects of current clinical interest. We highlight the role of multidisciplinary referral units in the diagnosis and treatment of these conditions.

Recent progress in end-stage hypertrophic cardiomyopathy.

Within the diverse spectrum of hypertrophic cardiomyopathy (HCM), a unique subgroup characterized by left ventricular enlargement and systolic dysfunction has emerged (defined as end-stage HCM [ES-HCM]). This underestimated entity provides challenging treatment strategies for extremely high risk of refractory heart failure and sudden cardiac death. Over the last 2 decades, the clinical features of ES-HCM have expanded and the underlying mechanisms gradually elucidated. Moreover, there is increasing evidence for early recognition of ES-HCM. New insights into early prevention and management will improve the clinical outcomes of this entity.

Optimized pacing mode for hypertrophic cardiomyopathy: Impact of ECG fusion during pacing.

BACKGROUND: Electrocardiographic (ECG) fusion with intrinsic QRS could reduce the benefit of atrial synchronous biventricular pacing (AS-BiVP) in patients with hypertrophic obstructive cardiomyopathy (HOCM). OBJECTIVES: The purpose of this study was to assess the benefit of AS-BiVP and the influence of ECG fusion for reduction of left ventricular outflow tract gradient (LVOTG) in these patients. METHODS: Twenty-one symptomatic HOCM patients with severe LVOTG were included. Twelve patients were evaluated retrospectively for the prevalence of fusion and its influence on outcomes after AS-BiVP. Eleven patients (2 of the first population were also evaluated retrospectively) were prospectively included to evaluate the benefit of performing atrioventricular node ablation (AVNA) to achieve full ventricular capture if fusion was present during AS-BiVP. RESULTS: Seven of the first 12 patients (58%) had ECG fusion. After 54 ± 24 months of AS-BiVP, the presence of fusion was associated with lower values for reduction of resting, dynamic LVOTG and New York Heart Association (NYHA) class. In the prospectively evaluated patients, after 12 months of follow-up, resting LVOTG decreased from 98 ± 39 to 39 ± 24 mm Hg (P = .008); dynamic LVOTG decreased from 112 ± 38 to 60 ± 24 mm Hg (P = .013); NYHA class decreased from 2.8 ± 0.4 to 1.7 ± 0.6 (P = .014); endurance time during constant work rate cycling exercise (80% of peak oxygen consumption) increased from 399 ± 148 to 691 ± 249 seconds (P = .046); quality of life improved from 46 ± 22 to 22 ± 20 points (P = .02); and brain natriuretic peptide levels decreased from 318 ± 238 to 152 ± 118 pg/mL (P = .09). Eight of the 11 prospectively evaluated patients (73%) needed AVNA, which further decreased LVOTG from 108 ± 40 mm Hg at baseline to 89 ± 29 mm Hg after BiVP to 54 ± 22 mm Hg after AVNA (P = .003). CONCLUSION: As-BiVP that ensures no ECG fusion, by means of AVNA when needed, appears to be the optimal pacing mode in HOCM patients.

Fragmented QRS predicts heart failure progression in patients with hypertrophic cardiomyopathy.

BACKGROUND: Although fragmented QRS complex (frag-QRS) reflecting intra-ventricular conduction delay has been shown to be a prognostic marker for cardiac events, few data exist regarding the impact of frag-QRS on cardiac events in hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: Ninety-four HCM patients (56 male; mean age, 58 ± 17 years) were retrospectively investigated. Frag-QRS was defined as the presence of various RsR' patterns in at least 2 contiguous ECG leads. Major arrhythmic events (MAE) were defined as sudden cardiac death, and combined sustained ventricular tachycardia/ventricular fibrillation. New-onset atrial fibrillation (AF) was diagnosed based on ECG during provisional or routine medical examination. Heart failure (HF) with hospitalization was defined as hospital admission due to subjective or objective symptoms. Frag-QRS was detected in 31 patients (33%).TNNI3 was the most frequent disease-causing gene. Median follow-up was 4.6 years. The 4-year cumulative survival rates of cardiac death, MAE, new-onset AF and HF with hospitalization were 97.6%, 94.6%, 87.5% and 89.3%, respectively. On multivariate analysis, frag-QRS was significantly associated with HF with hospitalization (adjusted hazard ratios [95% confidence intervals]: 5.4 [1.2-36], P=0.03). Moreover, HF-free survival was significantly lower in the frag-QRS (+) group compared to the frag-QRS (-) group (79.0% vs. 95.1%, P=0.03). CONCLUSIONS: Frag-QRS is associated with HF with hospitalization in HCM patients who had a unique distribution of gene mutations.

Extreme septal hypertrophy in an adolescent with congenital familial hypertrophic cardiomyopathy

No abstract available.

Novel α-actinin 2 variant associated with familial hypertrophic cardiomyopathy and juvenile atrial arrhythmias: a massively parallel sequencing study.

BACKGROUND: Next-generation sequencing might be particularly advantageous in genetically heterogeneous conditions, such as hypertrophic cardiomyopathy (HCM), in which a considerable proportion of patients remain undiagnosed after Sanger. In this study, we present an Italian family with atypical HCM in which a novel disease-causing variant in α-actinin 2 (ACTN2) was identified by next-generation sequencing. METHODS AND RESULTS: A large family spanning 4 generations was examined, exhibiting an autosomal dominant cardiomyopathic trait comprising a variable spectrum of (1) midapical HCM with restrictive evolution with marked biatrial dilatation, (2) early-onset atrial fibrillation and atrioventricular block, and (3) left ventricular noncompaction. In the proband, 48 disease genes for HCM, selected on the basis of published reports, were analyzed by targeted resequencing with a customized enrichment system. After bioinformatics analysis, 4 likely pathogenic variants were identified: TTN c.21977G>A (p.Arg7326Gln); TTN c.8749A>C (p.Thr2917Pro); ACTN2 c.683T>C (p.Met228Thr); and OBSCN c.13475T>G (p.Leu4492Arg). The novel variant ACTN2 c.683T>C (p.Met228Thr), located in the actin-binding domain, proved to be the only mutation fully cosegregating with the cardiomyopathic trait in 18 additional family members (of whom 11 clinically affected). ACTN2 c.683T>C (p.Met228Thr) was absent in 570 alleles of healthy controls and in 1000 Genomes Project and was labeled as Damaging by in silico analysis using polymorphism phenotyping v2, as Deleterious by sorts intolerant from tolerant, and as Disease-Causing by Mutation Taster. CONCLUSIONS: A targeted next-generation sequencing approach allowed the identification of a novel ACTN2 variant associated with midapical HCM and juvenile onset of atrial fibrillation, emphasizing the potential of such approach in HCM diagnostic screening.

[Renin-angiotensin-aldosterone system in hypertrophic cardiomyopathy].

Keeping in mind an important role of renin-angiotensin aldosterone system (RAS) in developing of cardiac remodeling and fibrosis, genetic polymorphisms coding its components could have influence with clinical variants of the course. Biomarkers could appear predictors of adverse. To examine the contribution of the RAS to developing of different hypertrophic cardiomyopathy (HCM) clinical variants of the course we studied 58 patients with HCM and controls comparable by age and gender. All patients were genotyped of gene polymorphisms CMA1 A(-1903)G rs1800875, AGTM235T rs699, AGTR1 A1166C rs5186, CYP11B2-344 T/C rs1799998. Angiotensin-converting enzyme (ACE) and angiotensin II (AII) levels were measured in 40 patients with HCM and 39 controls. We found out that AII were significantly decreased in patients with HCM than in healthy controls. The positive correlation between AII and left ventricle posterior wall (LVPW) were detected. Severity of heart hypertrophy were associated with pejorative genotype of AGT M235T polymorphism and CMA1 A(-1903) polymorphism. Significant association between the AG genotype of CMA1 A(-1903) polymorphism and angina class II-III and ventricular extrasystole of high gradation was observed. Our data not only support the hypothesis that RAAS polymorphisms may influence phenotype, but also allow for create new approaches to possible predicting adverse outcomes.