Risk assessment for Sudden Cardiac Death (SCD) and myocardial function

Sudden cardiac death (SCD) is still a challenge in cardiology. Mechanical Dispersion (MD) assessed by myocardial strain from speckle tracking echocardiography can be used to predict risk for SCD in post-MI cases and genetic myocardial diseases. Cardiac genetic diseases predispose to SCD in young individuals. Ongoing research in the CCI is focusing on predicting life threatening ventricular arrhythmias and exploring cardiac function in patients at risk of SCD.


Comparison of patients with early phase arrhythmogenic right ventricular cardiomyopathy and right ventricular outflow tract ventricular tachycardia
Saberniak J, Leren IS, Haland TF, Beitnes JO, Hopp E, Borgquist R, Edvardsen T, Haugaa KH

Right ventricular outflow tract ventricular tachycardia (RVOT-VT) is supposed to be a relatively benign condition, while arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy predisposing to ventricular arrhythmias, heart failure and sudden cardiac death and therefore a far from a benign condition. Both entities may become symptomatic with the same type of arrhythmias from the outflow tract of the RV. Discrimination between overt ARVC and RVOT-VT may be obvious, however, comparison between early phase ARVC and RVOT-VT can be challenging and correct diagnosis is crucial. Totally, we included 165 patients: 44 consecutive RVOT-VT and 121 ARVC patients. Of the ARVC patients, 77 had overt ARVC and 44 had early phase ARVC disease. We investigated if ECG and cardiac imaging can help to discriminate early phase ARVC from RVOT-VT patients.

We showed that patients with early phase ARVC had structural abnormalities with lower RV ejection fraction, increased RV basal diameter and pronounced RV mechanical dispersion in addition to lower frequency of PVC by Holter compared to RVOT-VT patients. These parameters may help correct diagnosis in patients with unclear phenotypes.

Upper panels: Echocardiographic longitudinal strain curves from RV free wall and  contraction inhomogenity, expressed as  mechanical dispersion (MD) from  a RVOT patient, an early phase ARVC patient and an ARVC patient with overt disease. Early phase ARVC and overt ARVC patients had pronounced MD compared to RVOT-VT patient. Lower panels: Measures of RV basal diameters in these patients. Patients with early phase ARVC (mid panel) had larger diameters compared to patients with RVOT-VT (left panel). From Saberniak J. et al, Eur Heart J Cardiovasc Imaging 2017 Jan;18(1):62-69.


Combination of ECG and Echocardiography for Identification of Arrhythmic Events in Early ARVC
Leren IS, Saberniak J, Haland TF, Edvardsen T, Haugaa KH

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic heart muscle disease with an increased risk of life threatening arrhythmias and sudden cardiac death. Arrhythmic events in ARVC are difficult to predict, particularly in the early phase of the disease. The aim of the study was to investigate early markers of arrhythmic events and improve risk stratification. We included 162 ARVC patients of whom 73 had early disease according to 2010 Task Force Criteria. We recorded patient history including previous arrhythmic events, performed resting and signal averaged electrocardiogram (ECG) and a standard 2D echocardiography including novel techniques as strain echocardiography.  A combination of electrical and echocardiographic parameters improved identification of subjects with arrhythmic events in early ARVC disease.

Measurement of Right ventricular diameter and right ventricular mechanical dispersion in ARVC patients. From Leren IS. et al, JACC Cardiovasc Imaging 2016 Oct 14 [Epub ahead of print].


Strain echocardiography is related to Fibrosis and Ventricular Arrhythmias in Hypertrophic Cardiomyopathy
Haland TF, Almaas VM, Hasselberg NE, Saberniak J, Leren IS, Hopp E, Edvardsen T, Haugaa KH

Hypertrophic cardiomyopathy patients (HCM) are at risk of ventricular arrhythmias. We aimed to explore if systolic function by strain echocardiography is related to ventricular arrhythmias (VAs) and to the extent of fibrosis by cardiac magnetic resonance imaging.

We included 150 HCM patients and 50 healthy individuals. We found that global longitudinal strain, pronounced mechanical dispersion and fibrosis were markers of VAs in HCM patients (Figure 1). Mechanical dispersion was a strong independent predictor of VAs and related to the extent of fibrosis. Strain echocardiography may improve risk stratification of VAs in HCM.

Mechanical dispersion by strain echocardiography in two patients with hypertrophic cardiomyopathy. Left panel displays longitudinal strain curves and mechanical dispersion in an HCM patient without ventricular arrhythmias. Horizontal white arrows indicate time to peak strain defined as the time from onset of Q/R to peak negative strain in each segment. Right panel shows more pronounced mechanical dispersion in a HCM patient with ventricular arrhythmias. From Haland TF. et al, Eur Heart J Cardiovasc Imaging 2016 Jun;17(6):613-21.

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