Hypersynchrony in sarcomeric hypertrophic cardiomyopathy: description and mechanistic approach using multimodal electro-mechanical non-invasive cartography (HSYNC study).

Background: Little is known about left ventricular (LV) sequences of contraction and electrical activation in hypertrophic cardiomyopathy (HCM). A better understanding of the underlying relation between mechanical and electrical activation may allow the identification of predictive response criteria to right ventricular DDD pacing in obstructive patients. Objective: To describe LV mechanical and electrical activation sequences in HCM patients compared to controls. Materials and methods: We prospectively studied, in 40 HCM patients (20 obstructive and 20 non-obstructive) and 20 healthy controls: (1) mechanical activation using echocardiography at rest and cardiac magnetic resonance imaging, (2) electrical activation using 3-dimensional electrocardiographic mapping (ECM). Results: In echocardiography, healthy controls had a physiological apex-to-base delay (ABD) during contraction (23.8 ± 16.2 ms). Among the 40 HCM patients, 18 HCM patients presented a loss of this ABD (<10 ms, defining hypersynchrony) more frequently than controls (45% vs. 5%, p = 0.017). These patients had a lower LV end-diastolic volume (71.4 ± 9.7 ml/m2 vs. 82.4 ± 14.8 ml/m2, p = 0.01), lower native T1 values (988 ± 32 ms vs. 1,028 ± 39 ms, p = 0.001) and tended to have lower LV mass (80.7 ± 23.7 g/m2 vs. 94.5 ± 25.3 g/m2, p = 0.08) compared with HCM patients that had a physiological contraction sequence. There was no significant relation between ABD and LV outflow tract obstruction. While HCM patients with a physiological contraction sequence presented an ECM close to those encountered in controls, patients with a loss of ABD presented a particular pattern of ECM with the first potential more frequently occurring in the postero-basal region. Conclusion: The LV contraction sequence can be modified in HCM patients, with a loss of the physiological ABD, and is associated with smaller LV dimensions and a particular pattern of ECM. Further research is needed to determine whether this pattern is related to an electrical substrate or is the consequence of the hypertrophied heart's specific geometry. Clinical trial registration: ClinicalTrial.gov: NCT02559726.

Venous dysfunction in obstructive hypertrophic cardiomyopathies: Results from the "HCM-Vein" pilot study.

Background: Hypertrophic cardiomyopathies (HCM) can be complicated by left ventricular outflow-tract obstruction (LVOTO) responsible for disabling exercise symptoms, a phenomenon influenced by hemodynamic factors including venous return. Methods: We aimed to evaluate venous dysfunction in obstructive HCM patients compared to healthy controls, and to investigate the relationship between venous dysfunction parameters and LVOTO in HCM. This is a clinical, monocentric, prospective, pilot study, in a tertiary care center. We investigated venous function using venous air plethysmography, and endothelial function. Results: Among the 30 symptomatic obstructive HCM patients, 30% (n = 9) presented abnormal venous residual volume fraction (RVFv) which translates in elevated ambulatory venous pressure vs. 0% in the 10 healthy controls (p < 0.05). Comparing obstructive HCM patients with abnormal RVFv (n = 9) to other obstructive HCM patients with normal RVFv (n = 21), there were no significant differences in terms of age, sex (67% male), and classical echocardiographic parameters both at rest and during exercise, except for left ventricular end-diastolic volume index which was significantly lower in the group with abnormal RVFv compared to the other HCM patients (40.1 ± 9.0 ml/m2 vs. 50.2 ± 10.6 ml/m2, p = 0.01). Fifty six percent of obstructive HCM patients with abnormal RVFv had an absolute increase in Willebrand factor (vs. 26% of other obstructive HCM patients, p < 0.05). Conclusions: In this pilot monocentric study, venous insufficiency was observed in about 30% of symptomatic obstructive HCM patients. Patients with venous insufficiency had more frequently a smaller LV cavity volume. Due to the small sample size, this study is only hypothesis-generating, and further investigations are needed.

Eclipsed Functional Mitral Regurgitation Destabilizing Hypertrophic Cardiomyopathy: An Unusual Case Treated With MitraClip.

MitraClip (Abbott Laboratories, Abbott Park, IL) is validated in high-risk patients with severe degenerative mitral regurgitation (MR); however, it is not well established for functional MR in hypertrophic cardiomyopathy (HCM). We share a case of a 68-year-old man with HCM hospitalized for multiple incidents of acute pulmonary edema caused by a dynamic MR and successfully treated with the MitraClip device. Novel teaching points emerging from this case are that MRs in HCM can often be explained by mixed mechanisms, and properly identifying the MR mechanism is essential to choose optimal treatment. Furthermore, MitraClip can simultaneously treat MR secondarily to annular dilation and systolic anterior motion.

Il a été établi démque Le Mitraclip (Abbott Laboratories, Abbott Park, Il) est une intervention percutanée validée pour la prise en charge des patients à haut risque chirurgical qui présente une régurgitation mitrale (RM) sévère dégénérative. Toutefois, cette technique est moins bien établie dans une RM fonctionnelle dans le cadre d'une cardiomyopathie hypertrophique (CMH). Nous faisons part d'un cas d'un homme de 68 ans atteint d'une CMH et hospitalisé en raison de multiples œdèmes aigus du poumon causés une la RM dynamique dont le traitement par MitraClip s'est avéré une réussite. Les nouveaux d'enseignement à enseigner qui émergent de ce cas portent sur le fait que les RM dans le cadre d'une CMH s'expliquent souvent par des mécanismes mixtes et que la détermination exacte du mécanisme de la RM est essentielle pour choisir le traitement qui convient le mieux au patient. De plus, le MitraClip permet de traiter simultanément les deux mécanismes d'une RM due à une dilatation annulaire et au mouvement systolique antérieur.

Characterization of Fabry Disease cardiac involvement according to longitudinal strain, cardiometabolic exercise test, and T1 mapping.

In Anderson-Fabry disease (FD), we sought to evaluate relation between left ventricular (LV) hypertrophy, longitudinal strain (LS), myocardial T1 mapping and cardiopulmonary exercise parameters, and their prognostic value in term of cardiovascular outcomes. In this prospective, observational, monocentric study called "FABRY-Image", we evaluated consecutive adult FD patients by echocardiography, cardiac magnetic resonance, and cardiopulmonary exercise testing. We investigated regional LS, the relations between LV hypertrophy, LS, T1 mapping, and VO2 peak and VE/VCO2, and the prediction of cardiovascular events during follow-up. From 2016 to 2019, we included 35 FD patients (44 ± 17 years, 40% male), that were compared with 20 controls. In FD patients, global, basal and mid-LV LS, as well as mean T1 were significantly altered compared to controls (p < 0.05) with relative apical LS sparing. LV wall thickness was particularly related to mean of basal LS (r = - 0.73), to T1 (r = - 0.48), and to VE/VCO2 (r = 0.45). Mean of basal LS was well related to myocardial T1 (r = 0.59). A good relation was observed between VO2 peak and global LS (r = 0.39) while VE/VCO2 slope was more related to maximal LV wall thickness (r = 0.45), and T1 (r = - 0.61). During a median follow-up of 2.4 years, 6/31 patients presented de novo atrial fibrillation or stroke. In Cox univariate analyses, LV wall thickness, basal LS, T1 value, and VE/VCO2 were significantly predictive of occurrence of de novo atrial fibrillation or stroke (p < 0.05). Our study shows an apical LS sparing in FD patients as observed in amyloidosis, and a close relation between LV hypertrophy, LS, T1 mapping, and VE/VCO2 which are all associated to the occurrence of de novo atrial fibrillation or TIA/stroke during follow-up. These results need to be confirmed by future multicentric studies.

Patients with high left ventricular filling pressure may be missed applying 2016 echo guidelines: a pilot study.

2016 guidelines for the echographic evaluation of left ventricular filling pressure (LVFP) proposed a single algorithm with limited number of criteria (E/A ratio, tricuspid regurgitation velocity, left atrial volume index and average E/e') mainly related to left atrial pressure. Pulmonary venous flow analysis, evaluating more specifically left ventricular end diastolic pressure (LVEDP) has been withdrawn. We aim to evaluate the proportion of patients diagnosed with normal LVFP according to 2016 recommendations, despite an abnormal pulmonary venous flow profile suggesting high LVEDP. We prospectively studied patients with stable ischemic cardiomyopathy and aortic stenosis, before cardiac surgery. Extensive echocardiography was performed including pulmonary and mitral A wave durations. We included 76 patients (mean age 72 ± 10 years, 78% were men), 37 (49%) with aortic stenosis and 22 (29%) with ischemic cardiomyopathy. Mean left ventricular ejection fraction was 67 ± 11%. Applying recommendations, 58 patients had normal LVFP and 15 patients had high LVFP. Among the 58 patients with normal LVFP, 26 patients had Apd-Amd duration > 30 ms highly suggestive of high LVEDP. These patients had higher LV mass (112 ± 30 g/m2 vs. 86 ± 20 g/m2, p = 0.004) and shorter A wave duration (120 ± 13.6 ms vs. 132 ± 16.5 ms, p = 0.006) as compared to the remaining 15 patients with concordant evaluation (normal LVFP and normal Apd-Amd). In the present study, we found that 26/58 patients with low LVFP according to the 2016 recommendations had Apd-Amd suggestive of high LVEDP. Pulmonary venous flow should be added to the algorithm, particularly in patients with unexplained symptom, high LV mass or truncated mitral A wave.