Left Ventricular Outflow Tract Pressure Gradient Research Articles

Deep learning of echocardiography distinguishes between presence and absence of late gadolinium enhancement on cardiac magnetic resonance in patients with hypertrophic cardiomyopathy

BackgroundHypertrophic cardiomyopathy (HCM) can cause myocardial fibrosis, which can be a substrate for fatal ventricular arrhythmias and subsequent sudden cardiac death. Although late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) represents myocardial fibrosis and is associated with sudden cardiac death in patients with HCM, CMR is resource-intensive, can carry an economic burden, and is sometimes contraindicated. In this study for patients with HCM, we aimed to distinguish between patients with positive and negative LGE on CMR using deep learning of echocardiographic images.MethodsIn the cross-sectional study of patients with HCM, we enrolled patients who underwent both echocardiography and CMR. The outcome was positive LGE on CMR. Among the 323 samples, we randomly selected 273 samples (training set) and employed deep convolutional neural network (DCNN) of echocardiographic 5-chamber view to discriminate positive LGE on CMR. We also developed a reference model using clinical parameters with significant differences between patients with positive and negative LGE. In the remaining 50 samples (test set), we compared the area under the receiver-operating-characteristic curve (AUC) between a combined model using the reference model plus the DCNN-derived probability and the reference model.ResultsAmong the 323 CMR studies, positive LGE was detected in 160 (50%). The reference model was constructed using the following 7 clinical parameters: family history of HCM, maximum left ventricular (LV) wall thickness, LV end-diastolic diameter, LV end-systolic volume, LV ejection fraction < 50%, left atrial diameter, and LV outflow tract pressure gradient at rest. The discriminant model combining the reference model with DCNN-derived probability significantly outperformed the reference model in the test set (AUC 0.86 [95% confidence interval 0.76–0.96] vs. 0.72 [0.57–0.86], P = 0.04). The sensitivity, specificity, positive predictive value, and negative predictive value of the combined model were 0.84, 0.76, 0.78, and 0.83, respectively.ConclusionCompared to the reference model solely based on clinical parameters, our new model integrating the reference model and deep learning-based analysis of echocardiographic images demonstrated superiority in distinguishing LGE on CMR in patients with HCM. The novel deep learning-based method can be used as an assistive technology to facilitate the decision-making process of performing CMR with gadolinium enhancement.

Three-Tesla Magnetic Resonance Imaging Characteristics of Hypertrophic Cardiomyopathy: A Comparison with Several Echocardiography Parameters.

Hypertrophic cardiomyopathy (HCM) is a primary cardiac disorder characterized by myocardial hypertrophy without increased afterload. This study set out to describe the cardiac magnetic resonance (CMR) imaging characteristics of HCM and to evaluate correlations of selected CMR parameters with echocardiography. This cross-sectional study enrolled 46 patients diagnosed at the Vietnam Heart Institute with HCM and underwent CMR at the Radiology Center, Bach Mai Hospital, from July 2021 to September 2022. A left ventricular outflow tract (LVOT)/aortic valve (AO) diameter ratio of ≥0.38 on CMR was consistent with an LVOT pressure gradient (PG) of <30 mmHg on echocardiography. The LVOT diameter and the LVOT/AO diameter ratio differed significantly between obstructive and non-obstructive HCM. The predominant phenotypes were diffuse asymmetric HCM (32.6%) and septal HCM (37%), followed by apical HCM (6.5%). Most late gadolinium enhancement (LGE) lesions were observed in the mid-wall of the hypertrophic segments. The mean LGE mass was significantly higher in the obstructive group than in the non-obstructive HCM group (p < 0.05). A strong negative correlation (r = -0.66) was found between the LVOT/AO diameter ratio on the CMR and the LVOT PG via echocardiography. Moreover, echocardiography detected morphologic risk factors for sudden cardiac death (SCD) in 80.4% of patients, whereas the corresponding proportion detected by CMR was 91.3%. Patients with systolic anterior motion (SAM) had a risk for a LVOT/AO diameter ratio <0.38, which was 5.7 times the risk observed in their counterparts without SAM. The LVOT/AO diameter ratio detected by CMR is a precise index for classifying hemodynamic HCM groups. CMR was better than echocardiography for SCD risk stratification.

Usefulness of exercise stress echocardiography for predicting cardiovascular events and atrial fibrillation in hypertrophic cardiomyopathy

BackgroundIn hypertrophic cardiomyopathy (HCM), the determinants of exercise tolerance and the usefulness of exercise stress echocardiography (ESE) for predicting hard endpoints have not been fully investigated. We aimed to assess the key parameters of ESE for exercise tolerance and the factors predictive of cardiovascular events and new-onset atrial fibrillation (AF) in patients with HCM. MethodsSeventy-four consecutive patients with HCM who underwent ESE and with an ejection fraction ≥50 % were enrolled. The primary endpoint was a composite of cardiovascular death, heart failure hospitalization, ventricular fibrillation or tachycardia, and ventricular assist device implantation. The secondary endpoint was new-onset AF. ResultsThe primary endpoint occurred in 13 patients. The left and right ventricular functions during exercise were responsible for decreased exercise tolerance. Peak exercise e′ and tricuspid annular plane systolic excursion (TAPSE) significantly predicted increased primary outcome risk (hazard ratio 1.35, 95 % confidence interval 1.10–1.76, p = 0.003; hazard ratio 1.19, 95 % confidence interval 1.07–1.32, p = 0.002, respectively), and the results were consistent even after adjustment by maximum workload. These ESE parameters improved the prognostic model containing estimated glomerular filtration rate (eGFR) and left atrial (LA) volume index. In AF-naive patients (n = 58), LA volume, peak exercise LA reservoir strain, and left ventricular outflow tract (LVOT) pressure gradient predicted new-onset AF. ConclusionsIn patients with HCM, ESE parameters related to left and right ventricular function were responsible for low exercise tolerance. Furthermore, e′ and TAPSE at peak workload could be useful for predicting cardiovascular events in addition to eGFR and LA volume index. LVOT pressure gradient and LA function during exercise predicted new-onset AF.

Simultaneous alcohol septal ablation and intravascular imaging-guided percutaneous transluminal coronary angioplasty – An effective approach in patients with hypertrophic obstructive cardiomyopathy and critical coronary artery disease

Abstract We report a case of symptomatic hypertrophic obstructive cardiomyopathy refractory to medical management with a left ventricular outflow tract pressure gradient (LVOTPG) of 160 mmHg associated with a significant calcific coronary artery disease treated using simultaneous percutaneous transluminal septal myocardial ablation (PTSMA) and an intravascular imaging-guided percutaneous transluminal coronary angioplasty. The left anterior descending artery stenosis distal to the third septal perforator was stented using a drug-eluting stent under optical coherence tomography guidance. Subsequently, the LVOTPG was addressed using PTMSA. Following the procedure, the patient had an uncomplicated recovery. A follow-up echo revealed an LVOTPG of 15 mmHg 4 weeks later.

Comparative Evaluation of Alcohol Septal Ablation: Left Anterior Descending Versus Non-left Anterior Descending Artery Approaches

Alcohol septal ablation (ASA) is performed for symptomatic drug-refractory hypertrophic obstructive cardiomyopathy to reduce the left ventricular outflow tract pressure gradient (LVOTPG) by injecting ethanol into a septal branch that perforates the septal bulge. The target septal branches usually arise directly from the left anterior descending (LAD) artery; however, vessels from a non-LAD artery can be selected in some cases. This study aimed to compare effectiveness and safety between ASA performed using a septal branch arising from a non-LAD artery and a branch arising from the LAD artery. This single-center, retrospective, observational cohort study comprised patients with hypertrophic obstructive cardiomyopathy who underwent ASA at the Gifu Heart Centre between 2011 and 2022. The effectiveness and safety of ASA using the 2 artery types were compared. The primary endpoints were LVOTPG and procedure success, determined as LVOTPG <30 mmHg after 1 year. Of 33 patients (mean age: 66.4 ± 13.0 years; 13 males), 18 patients who underwent ASA using only LAD branches and 15 patients who underwent ASA using only non-LAD branches demonstrated no significant difference in the decrease in LVOTPG during the follow-up period (−99.1 ± 47.4 mmHg/year vs. −75.7 ± 39.2 mmHg/year, respectively, P = 0.19). The procedure success at 1 year was not significantly different between the 2 groups (93.3% and 84.6%, respectively, P = 0.58). ASA performed using septal branches from non-LAD arteries could be an alternative treatment approach when appropriate septal branches are missing or desirable effects cannot be obtained from ASA using LAD branches.

Non-obstructive hypertrophic cardiomyopathy exhibit subclinical abnormalities in systolic and diastolic ventricular kinetic energy and systolic haemodynamic forces on 4D flow CMR

Abstract Background Patients with non-obstructive hypertrophic cardiomyopathy (nHCM) exhibit a range of anatomical variations including septal, reverse septal, apical, and concentric hypertrophy. Cardiovascular magnetic resonance imaging (CMR) with 4D flow permits assessment of haemodynamic forces (HDF) and kinetic energy (KE) of intraventricular blood flow (1,2). These parameters may indicate subclinical flow inefficiencies which may not be detectable on routine transthoracic echocardiography (3,4). The aim of this study was therefore to investigate if left ventricular (LV) HDF and KE differ between nHCM and controls, and between subgroups of nHCM. Methods Patients with nHCM (n=71) and age- and sex-matched controls (n=20) underwent CMR at 3T (Trio, Siemens) (Table 1). Patients were categorised as phenotype positive (P+) based on presence of hypertrophy (maximum wall thickness ≥15mm, or ≥13mm with a positive family history), and as phenotype negative (P-) referring to pre-hypertrophic sarcomeric variant carriers. Patients with P+ nHCM were classified into subgroups based on the pattern of hypertrophy. Left ventricular HDF and KE were computed over the cardiac cycle using validated modules (1) (Figure 1). Measurements of HDF were based on the Navier-Stokes equations (1), and analysed in three orthogonal directions as root mean square and peak values for systole and diastole. Force ratio was calculated as the sum of the two transverse components divided by the longitudinal component. The Mann-Whitney U test was used for group comparisons, Pearson analysis for correlations, and Fisher’s exact test for binary categorical data. Results P+, P- patients and controls had comparable LV ejection fraction from CMR, LV outflow tract pressure gradients, and diastolic parameters on echocardiography (Table 1). Systolic HDF and force ratio were increased, primarily in the lateral wall-septum direction in septal and reverse septal P+ patients compared to controls, but did not differ in any other directions in P+ compared to P- patients and to controls (Table 1, Figure 1). Diastolic HDF and force ratio did not differ between groups. Systolic KE was increased in P+ patients compared to P- and to controls (Table 1, Figure 1), mainly through increased KE in patients with septal and reverse septal hypertrophy. P+ patients also had increased late diastolic (A-wave) KE relative to P- patients and to controls (Table 1). Both systolic KE and force ratio correlated with maximum wall thickness in patients (r=0.31, p=0.005; r=0.43, p&amp;lt;0.0001). Conclusion In non-obstructive hypertrophic cardiomyopathy, left ventricular HDF and KE analysis from 4D flow CMR detect subclinical flow abnormalities. Increased systolic HDF and KE are linked to the extent and pattern of hypertrophy. Late diastolic A-wave KE was also abnormal in P+ patients despite normal diastolic velocities on echocardiography.Table 1Figure 1

Abstract 16562: Subclinical Flow Inefficiencies in Non-Obstructive Hypertrophic Cardiomyopathy Subgroups Revealed by 4D Flow Cardiovascular Magnetic Resonance

Background Patients with non-obstructive hypertrophic cardiomyopathy (nHCM) may exhibit flow inefficiencies despite normal flow profiles on transthoracic echocardiogram. We investigated whether left ventricular (LV) kinetic energy (KE) and hemodynamic forces (HDF) on 4D flow CMR are abnormal in nHCM, and examined the impact of genotype and hypertrophy phenotype on flow profiles. Methods 90 participants (70 HCM without echocardiographic outflow tract obstruction and 20 healthy controls) underwent 4D flow CMR. Patients were categorized as phenotype positive (P+) if they had LV hypertrophy (≥15mm or ≥13mm with an HCM family history), or phenotype negative (P-) referring to pre-hypertrophic pathogenic sarcomeric variant carriers. LV KE, HDF and transversal/longitudinal HDF ratio were computed from 4D flow CMR. Results P+ patients and controls were of similar age, but P- were younger. P+, P- and controls had comparable LV ejection fraction on CMR, and LV outflow tract pressure gradients and diastolic velocities on echocardiography (Table 1). Systolic KE was higher in P+ compared to controls (Table 1, Figure 1). Early diastolic KE was higher in P- than P+, reflecting younger P-, but did not differ between P+ and controls. Late diastolic KE was higher in P+ versus P- and controls. Systolic HDF ratio was higher in P+ than controls (Table 1, Figure 1). Diastolic HDF and HDF ratio were similar between P+ and controls. Conclusion Despite comparable flow velocities on echocardiography, nHCM exhibited higher systolic KE and HDF ratio, and late diastolic KE on 4D flow CMR relative to controls. Both the extent and pattern of hypertrophy are important determinants of abnormalities in KE and HDF.

Abstract 16368: Opioid Withdrawal-Induced Takotsubo Cardiomyopathy in Hypertrophic Cardiomyopathy

Introduction: This case highlights opioid withdrawal-induced Takotsubo cardiomyopathy (TCM) in a patient with pre-existing hypertrophic cardiomyopathy (HCM) and discusses the concurrent management. Clinical Presentation: An 85-year-old female with HCM, depression, and chronic back pain presented with generalized weakness five days after opioid discontinuation. She exhibited elevated troponin levels and ST elevation in anteroseptal leads, concerning for STEMI. Coronary angiogram revealed nonobstructive coronary artery disease. Transthoracic echocardiogram revealed newly reduced EF 45%, hyperdynamic basal left ventricle, and akinetic mid-distal left ventricle, consistent with TCM. Notably, marked basal anteroseptum thickness and systolic anterior mitral valve motion with left ventricular outflow tract obstruction (LVOTO) and a peak gradient of 92 mmHg. Presentation was complicated by hypotension, pulmonary edema and cardiorenal syndrome. β-blocker use initially deferred, opting for phenylephrine and diuresis until stabilization permitted β-blocker introduction. Discussion: We present a unique case of TCM precipitated by opioid withdrawal in a patient with existing HCM. Standard critical care management for TCM involves hemodynamic support until cardiac function recovers, though the use of vasopressors and inotropes remains controversial. Importantly, this case demonstrates severe provoked LVOTO, mimicking acute myocardial ischemia. Recognizing such scenarios is vital, as inappropriate use of vasodilators or inotropes can be fatal. Class I-IIa recommendations endorse β-blockers and vasoconstrictors for severe provoked LVOTO with hypotension and pulmonary edema. Phenylephrine, a selective α-agonist, maintains LVOT turgidity through preload enhancement, while β-blockers facilitate ventricular filling and reduce LVOT pressure gradient. Further research is warranted as current evidence level remains class C.

Impact of Premature Ventricular Complex (PVC) Burden on the Left Ventricle in the Structurally Normal Heart: Hemodynamic Alterations of Idiopathic PVC on Echocardiography.

Premature ventricular complex (PVC) without structural heart disease is mostly viewed as a benign arrhythmia. However, the high burden of PVC causes cardiomyopathy due to intraventricular dyssynchrony. The effects of ectopic contraction on left ventricular (LV) hemodynamics in the structurally normal heart are unclear. To examine the effect of PVC burden on LV dimension, LV systolic function, and intraventricular blood flow, and to determine whether ectopic ventricular contraction affects LV hemodynamics. Patients aged ≥ 18 years with PVC ≥ 5% on Holter recording were enrolled and divided into groups G1 (5-10%), G2 (10-20%), and G3 (≥ 20%). We excluded patients with structural heart diseases, pacemakers, and LV systolic dysfunction [LV ejection fraction (LVEF) < 50%]. Clinical characteristics and routine transthoracic echocardiography parameters were compared. The end-systolic LV internal dimension increased according to the PVC burden from G1 to G3 (p = 0.001). LVEF was inversely associated with PVC burden from G1 to G3 (p = 0.002). The same pattern was seen for LV outflow tract (LVOT) maximal velocity (p = 0.005) and maximal pressure gradient (PG) (p = 0.005), LVOT velocity time integral (VTI) (p = 0.03) and LV stroke volume index (LVSI) (p = 0.008). Systolic function and LV end-systolic dimension were inversely associated with PVC burden. Decreased LVOT flow velocity and PG were related to increased PVC burden. LVOT VTI and LVSI were smaller when the PVC burden exceeded 20%. These negative hemodynamic manifestations of idiopathic PVC were considerable even in structure normal hearts, hence the early elimination of PVC is strongly advised.

Detection of haemodynamic obstruction in hypertrophic cardiomyopathy using the sub-aortic complex: a cardiac MRI and Doppler study

To investigate the "sub-aortic complex (SAC)", a new cardiac magnetic resonance imaging (CMRI)-derived parameter, for the evaluation of left ventricular (LV) outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy (HCM), compared with conventional CMRI parameters and Doppler echocardiography. A total of 157 consecutive patients with HCM were recruited retrospectively. The patients were divided into two groups, 87 with LVOT obstruction and 70 without obstruction. The SAC was defined as a specific anatomical SAC affecting the LVOT, which were measured on the LV three-chamber steady-state free precession (SSFP) cine image at the end-systolic phase. The relations between the existence and severity of obstruction and SAC index (SACi) were evaluated using Pearson's correlation coefficient, receiver operating characteristic (ROC) curves, and logistic regression. The SACs were significantly different between the obstructive and non-obstructive groups. The ROC curves indicated that the SACi was able to discriminate obstructive and non-obstructive patients with the best predictive accuracy (AUC=0.949, p<0.001). The SACi was an independent predictor of LVOT obstruction and there was a significant negative correlation between resting LVOT pressure gradient and SACi (r=0.72 p<0.001). In the subgroup of patients with or without severe basal septal hypertrophy, the SACi was still able to predict LVOT obstruction with excellent diagnostic accuracy (AUC=0.944 and 0.948, p<0.001, respectively). The SAC is a reliable and straightforward CMRI marker for assessing LVOT obstruction. It is more effective than CMRI two-dimensional flow in diagnosing the severity of obstruction in patients with HCM.

Alcohol septal ablation versus surgical septal myectomy of obstructive hypertrophic cardiomyopathy: systematic review and meta-analysis.

To elucidate the optimal septal reduction therapy for obstructive hypertrophic cardiomyopathy, we conducted a meta-analysis comparing alcohol septal ablation (ASA) and septal myectomy. MEDLINE, EMBASE and Cochrane CENTRAL were searched to identify studies investigating the outcomes of ASA and septal myectomy in patients with obstructive hypertrophic cardiomyopathy in January 2023. The primary outcome of interest was all-cause mortality in studies with ≥1 year of follow-up. The secondary outcomes of interest comprised left ventricular outflow tract (LVOT) pressure gradient reduction and reoperations of LVOT. A subgroup analysis of all-cause mortality including studies with follow-up ≥5 years was performed. 27 observational studies were included (15 968 patients). Analysis demonstrated similar all-cause mortality [hazard ratio (HR) (95% confidence interval) (CI) 1.24 (0.88-1.76); P = 0.21; I2 = 56%]. In contrast, ASA was associated with less reduction of LVOT pressure gradient and a reoperation rate [weighted mean difference (95% CI) 11.04 mmHg (5.60-16.48); P < 0.01; I2 = 64%, HR (95% CI) 9.14 (6.55-12.75); P < 0.001; I2 = 0%, respectively]. The subgroup analysis with follow-up ≥5 years revealed higher long-term mortality with ASA [HR (95% CI) 1.50 (1.04-2.15); P = 0.03; I2 = 52%]. Although both septal reduction therapies were associated with similar all-cause mortality, ASA was associated with a higher rate of reoperation and less reduction of LVOT pressure gradient. Furthermore, all-cause mortality with follow-up ≥5 years showed favourable outcomes with septal myectomy, although the result is only hypothesis-generating given a subgroup analysis.

Effects of Aficamten on cardiac contractility in a feline translational model of hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is the most prevalent inherited cardiac disease in humans and cats and lacks efficacious pharmacologic interventions in the preclinical phase of disease. LV outflow tract obstruction (LVOTO) is commonly observed in HCM-affected patients and is a primary driver of heart failure symptoms and reduced quality of life. Novel small-molecule cardiac myosin inhibitors target actin-myosin interactions to alleviate overactive protein interactions. A prospective, randomized, controlled cross-over study was performed to evaluate pharmacodynamic effects of two doses (0.3 and 1 mg/kg) of a next-in-class cardiac myosin inhibitor, aficamten (CK-3773274, CK-274), on cardiac function in cats with the A31P MYBPC3 mutation and oHCM. Dose-dependent reductions in LV systolic function, LVOT pressure gradient, and isovolumetric relaxation times compared to baseline were observed. Promising beneficial effects of reduced systolic function warrant further studies of this next-in-class therapeutic to evaluate the benefit of long-term administration in this patient population.

Routine histopathology of septal myectomy for hypertrophic obstructive cardiomyopathy in a greek cohort.

Hypertrophic cardiomyopathy (HCM) is a diverse inherited disease affecting 1 in 500 individuals irrespective of gender and ethnicity. A fraction of HCM patients will eventually develop drug refractory dynamic obstruction of the left ventricular outflow tract. For such patients, septal myectomy is the procedure of choice to alleviate their symptoms and improve their quality of life. The current histopathological study, the first from the Greek region, aims to examine the hallmark histopathological characteristics of Hypertrophic Obstructive Cardiomyopathy in a population of patients undergoing septal myectomy at a single center over a ten year period. Medical records and histopathology specimens of thirty nine (n=39) patients were evaluated. The sample comprised 22 males (56.4%) and 17 females (43.6%). Mean patient age at myectomy was 53.9±16.7 years, ranging from 12 to 79 years. Maximal IVS thickness on echocardiography was available for 35 patients with a median value of 2.08cm. Peak resting LVOT Pressure Gradient was available for 33 patients with a mean value of 104.88±44.20 mmHg. Central tendency of each histopathological attribute expressed as the median value was: moderate for myocyte hypertrophy, mild for cytoplasmic vacuolization, moderate for subendocardial fibrosis, moderate for interstitial fibrosis, mild for replacement fibrosis, moderate for myofibrillar disarray and mild for capillary stenosis. Myocyte hypertrophy, present in all specimens, was positively correlated with maximal IVS thickness (tau-b=0.43, p=0.002). Replacement fibrosis was positively correlated with the grade of microvascular stenosis (tau-b=0.45, p=0.004). LVEF was negatively correlated with the grade of interstitial fibrosis (tau-b=-0.43, p=0.035) and with the extent of myocardial fiber disarray (tau-b=-0.42, p=0.034). Histopathological attributes were not correlated with patient gender or age thus proving that HCM has a histological phenotype unique to each patient, mainly depending on each specific sarcomeric mutation.

Alcohol septal ablation markedly reduces energy loss in hypertrophic cardiomyopathy with left ventricular outflow tract obstruction: A four-dimensional flow cardiac magnetic resonance study.

BackgroundFunctional follow-up modalities of hypertrophic cardiomyopathy (HCM) with left ventricular (LV) outflow tract obstruction (LVOTO) subjected to alcohol septal ablation (ASA) are limited.MethodsThis retrospective cohort study included patients of HCM with LVOTO who underwent ASA and four-dimensional (4D) flow cardiac magnetic resonance imaging (MRI) both before and after ASA. We analyzed energy loss in one cardiac cycle within the three-chamber plane of the LV and aortic root, and compared between pre- and post-ASA measurements.ResultsOf the 26 included patients, 10 (39%) were male, and median age was 71 (interquartile range 58–78) years. ASA significantly reduced not only LVOT pressure gradient (70 [19–50] to 9 [3–16], P < 0.001), but also energy loss during one cardiac cycle within the three-chamber plane of the LV and aortic root (80 [65–99] to 56 [45–70], P < 0.001). A linear association was observed between the reductions of energy loss and pressure gradient (R2 = 0.58, P < 0.001).ConclusionsASA significantly reduced energy loss within the LV and aortic root as quantified by 4D flow MRI, reflecting the decreased cardiac workload. This approach is a promising candidate for serial functional follow-up in patients undergoing ASA.

4D flow MRI left atrial kinetic energy in hypertrophic cardiomyopathy is associated with mitral regurgitation and left ventricular outflow tract obstruction.

To noninvasively assess left atrial (LA) kinetic energy (KE) in hypertrophic cardiomyopathy (HCM) patients using 4D flow MRI and evaluate coupling associations with mitral regurgitation (MR) and left ventricular outflow tract (LVOT) obstruction. Twenty-nine retrospectively identified patients with HCM underwent 4D flow MRI. MRI-estimated peak LVOT pressure gradient (∆PMRI) was used to classify patients into non-obstructive and obstructive HCM. Time-resolved volumetric LA kinetic energy (KELA) was computed throughout systole. Average systolic (KELA-avg) and peak systolic (KELA-peak) KELA were compared between non-obstructive and obstructive HCM groups, and associations to MR severity and LVOT ∆PMRI were tested.The study included 15 patients with non-obstructive HCM (58.6 [45.9, 65.2] years, 7 females) and 14 patients with obstructive HCM (51.9 [47.6, 62.6] years, 6 females). Obstructive HCM patients demonstrated significantly elevated instantaneous KELA over all systolic time-points compared to non-obstructive HCM (P < 0.05). Obstructive HCM patients also demonstrated higher KELA-avg (14.8 [10.6, 20.4] J/m3 vs. 33.4 [23.9, 61.3] J/m3, P < 0.001) and KELA-peak (22.1 [15.9, 28.7] J/m3 vs. 57.2 [44.5, 121.4] J/m3, P < 0.001) than non-obstructive HCM. MR severity was significantly correlated with KELA-avg (rho = 0.81, P < 0.001) and KELA-peak (rho = 0.79, P < 0.001). LVOT ∆PMRI was strongly correlated with KELA metrics in obstructive HCM (KELA-avg: rho = 0.86, P < 0.001; KELA-peak: rho = 0.85, P < 0.001).In HCM patients, left atrial kinetic energy, by 4D flow MRI, is associated with MR severity and the degree of LVOT obstruction.

Minimally Invasive Surgery for Hypertrophic Obstructive Cardiomyopathy With Mitral Regurgitation

To summarize the safety and effect of minimally invasive surgery for hypertrophic obstructive cardiomyopathy (HOCM) with significant mitral regurgitation through a single transaortic approach via right minithoracotomy. From 2008 to 2017, 51 HOCM patients with significant mitral regurgitation underwent minimally invasive surgery via right minithoracotomy. Preoperative peak left ventricular outflow tract pressure gradient (LVOTPG) was 96.53 ± 28.72 mm Hg. Preoperative average interventricular septum thickness was 24.31 ± 3.52 mm. All patients had significant mitral regurgitation with systolic anterior motion phenomenon. An oblique incision was made on the anterior wall of ascending aorta or aortic root. Modified Morrow procedure and edge-to-edge mitral valvuloplasty were performed through the single transaortic approach via right minithoracotomy. All patients successfully underwent the minimally invasive surgery through the single transaortic approach via right minithoracotomy. At discharge, postoperative peak LVOTPG (18.16 ± 6.41 mm Hg) and interventricular septum thickness (14.33 ± 1.99 mm) were significantly decreased compared with preoperative values (P < .05). All patients had no or trivial mitral regurgitation. The average peak mitral valve pressure gradient was 3.39 ± 1.82 mm Hg. Systolic anterior motion phenomenon disappeared in all patients. During follow-up, peak LVOTPG was 19.27 ± 6.10 mm Hg; average interventricular septum thickness was 14.67 ± 1.87 mm. All patients had no or trivial mitral regurgitation. Average peak mitral valve pressure gradient was 3.04 ± 1.52 mm Hg. No systolic anterior motion phenomenon occurred. Minimally invasive surgery of modified Morrow procedure and edge-to-edge mitral valvuloplasty through a single transaortic approach via right minithoracotomy could be safely and effectively applied for patients with HOCM and significant mitral regurgitation, which could also effectively eliminate systolic anterior motion phenomenon and without mitral valve stenosis.

Increased heart rate with sleep disordered breathing in hypertrophic cardiomyopathy

BackgroundCurrent guidelines recommend medications with rate control properties for symptomatic patients with hypertrophic cardiomyopathy (HCM) based on the rationale that lowering heart rate (HR) improves their symptoms. Whether sleep disordered breathing (SDB) is associated with increased HR in HCM patients is not known. MethodWe diagnosed uncontrolled SDB (oxygen desaturation index ≥5) in consecutive echocardiographically confirmed HCM patients seen at Mayo Clinic, Rochester, and analyzed their HR as recorded by a 24-h Holter monitor. We compared mean, minimum, maximum HR between those with vs without SDB. In a pilot subanalysis of HCM patients with SDB who also underwent subsequent diagnostic polysomnography (PSG), we analyzed RR interval changes coinciding with obstructive sleep apnea and hypopnea episodes. ResultsOf the 230 HCM patients included in this study (age 54 ± 16 years; 138 male; LVOT pressure gradient at rest 45 ± 39 mmHg), 115 (50%) patients had SDB. HCM patients with SDB were recorded to have higher mean HR (71 vs. 67 bpm; p = .002, adjusted p = .001), and this difference was most pronounced during night hours of 10 PM to 5 AM (61 vs. 67 bpm; p < .001). In the pilot analysis of the available PSG data, the release of obstructive sleep apneas and hypopneas coincided with fluctuation of HR. ConclusionsSDB is independently associated with higher mean HR in patients with HCM, and this difference is most significant during sleep. Treatment of SDB, which is readily available, should be tested as a complementary modality to the currently recommended pharmacotherapy aimed at lowering HR in patients with symptomatic HCM.

Relationship between Left Ventricular Outflow Tract Pressure Gradient and Hemoglobin in Patients with Hypertrophic Cardiomyopathy.

Anemia caused by left ventricular outflow tract obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM) has been reported, however, large clinical studies confirming this association are lacking. The objective of the present study was to investigate the relationship between left ventricular outflow tract (LVOT) pressure gradient and hemoglobin in patients with hypertrophic cardiomyopathy (HCM). Patient demographics, laboratory and echocardiography data from 310 patients diagnosed with HCM from our hospital who had undergone echocardiography from July 2014 to March 2019 were collected from medical records. Patients were classified into HOCM and non-HOCM groups. Compared to the non-HOCM group, patients in the HOCM group had a lower hemoglobin level (112.2 ± 16.7 vs. 132.9 ± 22.2 g/L, p < 0.001). In addition, significant negative correlations between hemoglobin and LVOT pressure gradient were found in males (r = -0.568, p < 0.001) and females (r = -0.589, p < 0.001). Receiver operating characteristic curve analysis revealed that the best cut-off value for hemoglobin to predict HOCM in male patients was 128 g/L with 74.19% sensitivity and 75.51% specificity (area under the curve: 0.763, p < 0.001). For female patients, the cut-off value was 125 g/L, with a sensitivity and specificity of 89.39% and 48.48%, respectively (area under the curve: 0.718, p < 0.001). Our results indicate that hemoglobin level is inversely proportional to the LVOT gradient pressure and has value for predicting outflow tract obstruction in patients with HCM.

Correlation between three-dimensional speckle tracking echocardiography combined with cardiac magnetic resonance imaging-late gadolinium enchancemet on left ventricular global systolic function and myocardial fibrosis in adult hypertrophic cardiomyopathy

Objective To evaluate the left ventricular global systolic function and myocardial fibrosis in adult hypertrophic cardiomyopathy (HCM) patients by three-dimensional speckle tracking echocardiography(3D-STE) combined with cardiac magnetic resonance imaging-late gadolinium enchancemet (CMRI-LGE) sequence, and to explore the association between left ventricular global systolic function and myocardial fibrosis. Methods Thirty patients with HCM(HCM group) and 33 healthy controls(control group) were enrolled in the study. All patients underwent conventional two-dimensional echocardiography (2DE), tissue Doppler imaging (TDI), and 3D-STE. The following parameters were acquired and compared between the groups: interventricular septal end-diastolic thickness (IVSD), left ventricular posterior wall end-diastolic thickness (LVPWD), left ventricular mass(LVM), left ventricular mass index (LVMI), left atrial volume (LAV), and left ventricular end-systolic volume(LVESV), left ventricular end-diastolic volume (LVEDV), left ventricular outflow tract pressure gradient (LVOT-PG), left ventricular outflow tract velocity time integral (LVOT-VTI), isovolumic relaxation time (IVRT), global strain (GS), global longitudinal strain (GLS), global radial strain (GRS), global circumferential strain (GCS). And 28 patients who met the CMRI indications underwent CMRI-LGE to obtain the LVM, and the correlation and consistency of LVM results obtained from CMRI and 3D-STE were performed.According to LGE results, HCM patients were divided into LGE(+ ) group and LGE (-) group, the differences of GLS, GRS and GCS between the two groups were analyzed. Results ①Compared with the control group, IVSD, LVPWD, LVMI, LAV, LVOT-PG, LVOT-VTI and IVRT were significantly increased in the HCM group (all P 0.05), while GLS and GRS decreased and GCS increased significantly in HCM group (P<0.05); ③The correlation between 3D-STE and CMRI in measuring measured LVM in HCM patients was good, and the results showed good concordance(r=0.807, P<0.01). ④GLS in LGE(+ ) group was lower than in LGE(-) group(P=0.004), but there was no significant difference in GCS and GRS between the two groups(P=0.597, 0.534). Conclusions ①3D-STE can detect the early damage of left ventricular global systolic function in patients with HCM; ②3D-STE combined with CMRI-LGE technology can provide an important imaging reference for the evaluation of the relationship between left ventricular global systolic function and myocardial fibrosis in patients with HCM. Key words: Echocardiography; Three-dimensional speckle tracking imaging; Cardiomyopathy, hypertrophic; Cardiac magnetic resonance imaging; Ventricular function, left; Myocardial fibrosis

Assessment of bi-ventricular remodeling in patients with hypertrophic cardiomyopathy after modified Morrow surgery by three-dimensional speckle tracking echocardiography

Objective To assess the bi-ventricular remodeling in patients with hypertrophic obstructive cardiomyopathy (HOCM) after modified Morrow surgery by three-dimensional speckle tracking echocardiography (3D-STE). Methods Twenty-eight patients with HOCM who underwent modified Morrow surgery from August 2013 to September 2016 in Xijing Hospital were consecutively included in this study. Routine and full-volume echocardiographic images were collected before and after surgery, 3D-STE echocardiographic data were analyzed by TomTec software to calculate left and right ventricular end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF), as well as the longitudinal strain(LS), circumferential strain(CS), radial strain(RS) of the 16 segments of left ventricle. The left atrial maximum volume(LAVmax), left atrial minimum volume (LAVmin), left atrial stroke volume(LASV), left atrial ejection fraction(LAEF) were obtained, as well as right ventricular longitudinal strain of septum [RVLS(S)], right ventricular longitudinal strain of free wall[RVLS(FW)], tricuspid annular planesystolic excursion(TAPSE), right ventricular fractional area change(RVFAC). Results Compared with baseline, the IVS thickness were significantly reduced, LVOT pressure gradient were significantly decreased, LVOT diameter were increased significantly (all P<0.05). The LS in the basal part of anterior and lateral wall were increased significantly (all P<0.05). The CS in basal and middle part of lateral wall were increased significantly (all P<0.05). The RS in basal part of anterior, lateral and posterior wall, as well as in the middle part of anterior and lateral wall were increased significantly( all P<0.05). The LAVmax, LAVmin and LASV were decreased, and the LAEF was increased(all P<0.05). The RVLS(FW) and the TAPSE were increased significantly( all P<0.05). Conclusions After modified Morrow surgery in HOCM patients, the morphological remodeling of left ventricle, left atrium and right ventricle are improved, accompanied by the improvement of the function. 3D-STE is valuable in evaluating the efficacy of modified Morrow surgery in HOCM patients. Key words: Echocardiography; Speckle tracking imaging, three-dimensional; Cardiomyopathy, hypertrophic; Ventricular function