Functional, morphological and electrocardiographical abnormalities in patients with apical hypertrophic cardiomyopathy and apical aneurysm: correlation with cardiac MR

Different characteristics of apical aneurysm in hypertrophic cardiomyopathy are related to difference in long-term prognosis

BACKGROUND

Data regarding long-term cardiac and cerebrovascular adverse events in patients with hypertrophic cardiomyopathy (HCM) and apical aneurysm (AAn) are scarce and specific treatment strategies that include the use of anticoagulants have not yet been established. We aimed to evaluate the prevalence and long-term prognostic implication based on characteristics of AAn in patients with HCM.

METHODS

A total of 458 consecutive patients diagnosed with HCM underwent cardiovascular magnetic resonance imaging and echocardiography from August 1, 2008 to December 31, 2015. AAn was classified into Grade 1 and Grade 2 based on size and morphology. The patients were followed up for a median duration of 6.3 years (range, 4.2-8.7 years) for major adverse cardiac and cerebral events (MACCEs); a composite of cardiac death, HCM-related hospitalization, cerebrovascular accident (CVA), heart transplantation, myocardial infarction, and implantable cardiac defibrillator/cardiac resynchronization therapy.

RESULTS

AAn was detected in 9.2%. MACCEs developed more frequently in patients with AAn than in those without AAn (30.1% vs. 20.7%, P = 0.015), with the rate of CVA as the main difference (9.7% vs. 5.3%, P = 0.011). Grade 2 AAn group showed significantly higher MACCE than Grade 1 AAn group (41.8% vs. 21.9%, P < 0.001). In multivariate analysis, the presence of AAn was independently associated with increased risk of MACCEs (adjusted hazard ratio: 1.95; 95% confidence interval, CI: 1.16-3.28; P = 0.012).

CONCLUSIONS

AAn is independently associated with increased risk of HCM-related adverse events, especially cerebral infarction, with significant relationship between aneurysm size and adverse events.

Association of electrocardiographic markers with myocardial fibrosis as assessed by cardiac magnetic resonance in different clinical settings

BACKGROUND

Cardiac magnetic resonance (CMR) is a unique tool for non-invasive tissue characterization, especially for identifying fibrosis.

AIM

To present the existing data regarding the association of electrocardiographic (ECG) markers with myocardial fibrosis identified by CMR - late gadolinium enhancement (LGE).

METHODS

A systematic search was performed for identifying the relevant studies in Medline and Cochrane databases through February 2021. In addition, we conducted a relevant search by Reference Citation Analysis (RCA) (https://www.referencecitationanalysis.com).

RESULTS

A total of 32 studies were included. In hypertrophic cardiomyopathy (HCM), fragmented QRS (fQRS) is related to the presence and extent of myocardial fibrosis. fQRS and abnormal Q waves are associated with LGE in ischemic cardiomyopathy patients, while fQRS has also been related to fibrosis in myocarditis. Selvester score, abnormal Q waves, and notched QRS have also been associated with LGE. Repolarization abnormalities as reflected by increased Tp-Te, negative T-waves, and higher QT dispersion are related to myocardial fibrosis in HCM patients. In patients with Duchenne muscular dystrophy, a significant correlation between fQRS and the amount of myocardial fibrosis as assessed by LGE-CMR was observed. In atrial fibrillation patients, advanced inter-atrial block is defined as P-wave duration ≥ 120 ms, and biphasic morphology in inferior leads is related to left atrial fibrosis.

CONCLUSION

Myocardial fibrosis, a reliable marker of prognosis in a broad spectrum of cardiovascular diseases, can be easily understood with an easily applicable ECG. However, more data is needed on a specific disease basis to study the association of ECG markers and myocardial fibrosis as depicted by CMR.

Deciphering hypertrophic cardiomyopathy with electrocardiography

The comprehensive assessment of patients with hypertrophic cardiomyopathy is a complex process, with each step concurrently focusing on confirmation of the diagnosis, differentiation between sarcomeric and non-sarcomeric disease (phenocopy), and prognostication. Novel modalities such as genetic testing and advanced imaging have allowed for substantial advancements in the understanding of this condition and facilitate patient management. However, their availability is at present not universal, and interpretation requires a high level of expertise. In this setting, electrocardiography, a fast and widely available method, still retains a significant role in everyday clinical assessment of this population. In our review, we follow a stepwise approach for the interpretation of each electrocardiographic segment, discussing clinical implications of electrocardiographic patterns in sarcomeric disease, their value in the differential diagnosis from phenocopies, and impact on patient management. Outlining the substantial amount of information to be obtained from a simple tracing, we exhibit how electrocardiography is likely to remain an integral diagnostic tool in the future as well.

Cardiac MRI evaluation of myocardial disease

Cardiovascular magnetic resonance (CMR) is a key imaging technique for cardiac phenotyping with a major clinical role. It can assess advanced aspects of cardiac structure and function, scar burden and other myocardial tissue characteristics but there is new information that can now be derived. This can fill many of the gaps in our knowledge with the potential to change thinking, disease classifications and definitions as well as patient care. Established techniques such as the late gadolinium enhancement technique are now embedded in clinical care. New techniques are coming through. Myocardial tissue characterisation techniques, particularly myocardial mapping can precisely measure tissue magnetisation-T1, T2, T2* and also the extracellular volume. These change in disease. Key biological pathways are now open for scrutiny including focal fibrosis (scar) and diffuse fibrosis, inflammation, metabolism and infiltration. Other new areas to engage in where major insights are growing include detailed assessments of myocardial mechanics and performance, spectroscopy and hyperpolarised CMR. In spite of the advances, challenges remain, particularly surrounding utilisation, technical development to improve accuracy, reproducibility and deliverability, and the role of multidisciplinary research to understand the detailed pathological basis of the MR signal changes. Collectively, these new developments are galvanising CMR uptake and having a major translational impact on healthcare globally and it is steadily becoming key imaging tool.