Coronary Embolism Among Patients With ST-Segment-Elevation Myocardial Infarction and Atrial Fibrillation: An Underrecognized But Deadly Association.

BACKGROUND: The prevalence and impact of coronary emboli (CE) in patients with ST-segment-elevation myocardial infarction (STEMI) and atrial fibrillation (AF) have not been specifically studied. The objective was to describe the clinical characteristics and outcomes of patients with AF and CE in a large series of patients with STEMI. METHODS AND RESULTS: We investigated 2292 consecutive patients with STEMI and among them 225 patients with AF: 46 patients with a STEMI related to CE (group A) and 179 patients with a STEMI related to an atherosclerotic cause (group B). Compared with the 2067 patients without AF and CE (group C), patients with AF and CE were older (73 versus 59 years, P<0.05), more likely to be female (43% versus 22%, P<0.05), and presented more frequently with cardiogenic shock at admission (26% versus 9%, P<0.05). The baseline characteristics of patients with AF (group A versus B) did not differ significantly according to STEMI pathogenesis. In the unadjusted analysis, the 45-day mortality was higher in patients with CE and AF (group A versus group C: 20% versus 4%; P<0.05 and group A versus group B: 20% versus 8%, P=not significant); this trend persisted at 2-year follow-up (group A versus group C: 24% versus 6%; P<0.05 and group A versus group B: 24% versus 17%, P=not significant). After stabilized inverse exposure probability weighting adjustment, a higher 45-day mortality rate was confirmed in patients with CE and AF (group A versus group C: 18% versus 5%, P<0.05). CONCLUSIONS: In patients presenting with STEMI and AF, CE was associated with excess early mortality. REGISTRATION: URL: clinicaltrials.gov. Identifier: NCT05679843.

Bradycardia risk stratification with implantable loop recorder after unexplained syncope.

BACKGROUND: An implantable loop recorder is an effective tool for diagnosing unexplained syncope. However, after a first episode in non-high-risk patients, the usefulness of implantable loop recorder implantation remains unclear. AIMS: To analyse relevant risk factors for significant bradycardia in order to identify patients who do or do not benefit from implantable loop recorder implantation. Also, to study whether implantable loop recorder implantation with remote monitoring is associated with less recurrence of traumatic syncope. METHODS: This was a retrospective monocentric study including patients with implantable loop recorder implantation after unexplained syncope, using remote monitoring and iterative consultations. RESULTS: Two hundred and thirty-seven patients were implanted for unexplained syncope. Significant bradycardia occurred in 53 patients (22.4%): 23 (43.4%) caused by paroxysmal atrioventricular block and 30 (56.6%) caused by sinus node dysfunction, leading to permanent pacemaker implantation in 48 patients. Compared with younger patients, there was a 3.46-fold increase (95% confidence interval 1.92-6.23; P<0.0001) in the risk of significant bradycardia in patients aged≥60 years. Based on multivariable analysis, only "typical syncope" was associated with significant bradycardia occurrence (hazard ratio 3.14, 95% confidence interval 1.75-5.65; P=0.0001). There was no recurrence of significant bradycardia with traumatic complications among patients implanted for traumatic syncope. CONCLUSIONS: This study shows that: (1) implantable loop recorders identify more significant bradycardia in patients aged≥60 presenting with a first non-high-risk typical syncope, suggesting that an implantable loop recorder should be implanted after a first episode of unexplained syncope in such conditions; and (2) after traumatic syncope, implantable loop recorder implantation is safe, and is associated with little or no recurrence of traumatic syncope.

One-year mortality and causes of death after stereotactic radiation therapy for refractory ventricular arrhythmias: A systematic review and pooled analysis.

Patients treated with cardiac stereotactic body radiation therapy (radioablation) for refractory ventricular arrhythmias are patients with advanced structural heart disease and significant comorbidities. However, data regarding 1-year mortality after the procedure are scarce. This systematic review and pooled analysis aimed at determining 1-year mortality after cardiac radioablation for refractory ventricular arrhythmias and investigating leading causes of death in this population. MEDLINE/EMBASE databases were searched up to January 2023 for studies including patients undergoing cardiac radioablation for the treatment of refractory ventricular arrhythmias. Quality of included trials was assessed using the NIH Tool for Case Series Studies (PROSPERO CRD42022379713). A total of 1,151 references were retrieved and evaluated for relevance. Data were extracted from 16 studies, with a total of 157 patients undergoing cardiac radioablation for refractory ventricular arrhythmias. Pooled 1-year mortality was 32 % (95 %CI: 23-41), with almost half of the deaths occurring within three months after treatment. Among the 157 patients, 46 died within the year following cardiac radioablation. Worsening heart failure appeared to be the leading cause of death (52 %), although non-cardiac mortality remained substantial (41 %) in this population. Age≥70yo was associated with a significantly higher 12-month all-cause mortality (p<0.022). Neither target volume size nor radiotherapy device appeared to be associated with 1-year mortality (p = 0.465 and p = 0.199, respectively). About one-third of patients undergoing cardiac stereotactic body radiation therapy for refractory ventricular arrhythmias die within the first year after the procedure. Worsening heart failure appears to be the leading cause of death in this population.

Cardiac stereotactic radiation therapy for refractory ventricular arrhythmias in patients with left ventricular assist devices.

Left ventricular assist device (LVAD) implantation is an established treatment for patients with advanced heart failure refractory to medical therapy. However, the incidence of ventricular arrhythmias (VAs) is high in this population, both in the acute and delayed phases after implantation. About one-third of patients implanted with an LVAD will experience sustained VAs, predisposing these patients to worse outcomes and complicating patient management. The combination of pre-existing myocardial substrate and complex electrical remodeling after LVAD implantation account for the high incidence of VAs observed in this population. LVAD patients presenting VAs refractory to antiarrhythmic therapy and catheter ablation procedures are not rare. In such patients, treatment options are extremely limited. Stereotactic body radiation therapy (SBRT) is a technique that delivers precise and high doses of radiation to highly defined targets, reducing exposure to adjacent normal tissue. Cardiac SBRT has recently emerged as a promising alternative with a growing number of case series reporting the effectiveness of the technique in reducing the VA burden in patients with arrhythmias refractory to conventional therapies. The safety profile of cardiac SBRT also appears favorable, even though the current clinical experience remains limited. The use of cardiac SBRT for the treatment of refractory VAs in patients implanted with an LVAD are even more scarce. This review summarizes the clinical experience of cardiac SBRT in LVAD patients and describes technical considerations related to the implementation of the SBRT procedure in the presence of an LVAD.

Procedure-Related Complications of Catheter Ablation for Atrial Fibrillation.

BACKGROUND: Catheter ablation of atrial fibrillation (AF) is a commonly performed procedure. However, it is associated with potentially significant complications. Reported procedure-related complication rates are highly variable, depending in part on study design. OBJECTIVES: The purpose of this systematic review and pooled analysis was to determine the rate of procedure-related complications associated with catheter ablation of AF using data from randomized control trials and to assess temporal trends. METHODS: MEDLINE and EMBASE databases were searched from January 2013 to September 2022 for randomized control trials that included patients undergoing a first ablation procedure of AF using either radiofrequency or cryoballoon (PROSPERO, CRD42022370273). RESULTS: A total of 1,468 references were retrieved, of which 89 studies met inclusion criteria. A total of 15,701 patients were included in the current analysis. Overall and severe procedure-related complication rates were 4.51% (95% CI: 3.76%-5.32%) and 2.44% (95% CI: 1.98%-2.93%), respectively. Vascular complications were the most frequent type of complication (1.31%). The next most common complications were pericardial effusion/tamponade (0.78%) and stroke/transient ischemic attack (0.17%). The procedure-related complication rate during the most recent 5-year period of publication was significantly lower than during the earlier 5-year period (3.77% vs 5.31%; P = 0.043). The pooled mortality rate was stable over the 2 time periods (0.06% vs 0.05%; P = 0.892). There was no significant difference in complication rate according to pattern of AF, ablation modality, or ablation strategies beyond pulmonary vein isolation. CONCLUSIONS: Procedure-related complications and mortality rates associated with catheter ablation of AF are low and have declined in the past decade.

Impact of pulmonary veins anatomy on the outcomes of radiofrequency ablation for paroxysmal atrial fibrillation in the era of contact force-sensing ablation catheters.

BACKGROUND: Pulmonary vein (PV) isolation (PVI) has become the cornerstone of atrial fibrillation (AF) ablation in patients with paroxysmal AF (PAF). PVI durability is influenced by many factors including PVs anatomy. Data regarding the influence of PVs anatomical variations on the outcomes of PAF ablation in the era of contact force-sensing ablation catheters are scarce and contradictory. METHODS: Consecutive patients referred to our center for a first ablation of PAF using radiofrequency (RF) were included. PVs anatomy was classified into 3 groups: typical anatomy (4 distinct veins), left common ostium (LCO), and right accessory PV (RAPV). The primary outcome was recurrence of atrial arrhythmia episode during a 12-month follow-up after ablation. RESULTS: Two hundred twenty-three patients were included (mean age 58.4 ± 10.8 years and 70.9% male). Among this cohort, 141 patients (63.2%) had typical PV anatomy, 53 (23.8%) had a LCO, and 29 (13.0%) had a RAPV. The existence of a RAPV was not associated with a higher rate of AF recurrences (22 (14.3%) vs. 7 (10.1%), p = 0.519). After multivariate analysis, the presence of an LCO did not appear to be associated with the AF recurrence rate at 12 months (OR = 1.69, 95%CI 0.95-2.49, p = 0.098). Maintenance of antiarrhythmic drugs after ablation was the only factor independently associated with a decreased risk of AF recurrence at 12 months (OR = 0.76, 95%CI 0.60-0.97, p = 0.046). CONCLUSION: This study suggests that the presence of an LCO or a RAPV is not associated with a higher rate of AF recurrence at 12 months after radiofrequency PVI using contact force-sensing catheters in PAF patients.

How to use pace mapping for ventricular tachycardia ablation in postinfarct patients.

We aim to describe the technical aspects of pace mapping (PM), as well as the two typical patterns of pacing correlation maps during ventricular tachycardia (VT) ablation. The first main pattern is focal, with a gradual and eccentric decrease of the QRS correlation from the area with the best PM correlation. This focal pattern may be associated with two clinical situations: (1) with some endocardial points showing a good correlation compared to VT morphology: true endocardial exit of VT or endocardial breakthrough of either an intramural or an epicardial circuit; (2) without any endocardial points showing a good correlation compared to VT morphology: the VT may originate from the other ventricle, but the presence of an intramural or an epicardial circuit should be considered in patients with a structural heart disease. The second pattern is the presence of PM points exhibiting a good correlation close to other PM points showing a poor correlation compared to VT morphology: this abrupt change in paced QRS morphology over a short distance indicates divergence of activation wavefronts between these sites and suggests the presence of a slow conduction channel: the VT isthmus.

Catheter knot around the mitral valve apparatus: An exceptional complication of remote magnetic navigation.

Remote magnetic navigation (RMN) is as safe and effective as manual navigation for catheter ablation of ventricular arrhythmias. This case is the first description of a soft-tip ablation catheter entrapment in the mitral valve apparatus during an RMN ablation procedure. The tight knot created by the catheter around a mitral valve chordae required surgical removal. This complication, which has never been reported before, highlights the need for closer fluoroscopic monitoring when performing catheter loops inside the ventricles when using the RMN system.

Efficacy and Safety of Second and Third-Generation Laser Balloon for Paroxysmal Atrial Fibrillation Ablation Compared to Radiofrequency Ablation: A Matched-Cohort.

Laser balloon (LB) has emerged as an interesting strategy for pulmonary vein isolation in paroxysmal atrial fibrillation (AF). A third-generation LB has recently been developed, allowing a continuous ablation set. We aimed to compare the results from our center's experience with second and third-generation LBs to a cohort of matched patients who had undergone radiofrequency ablation (RFA) with contact-force catheters. This retrospective monocenter case-control study included our first 50 LB paroxysmal AF ablations (26 second and 24 third-generation LB) and 50 RFA controls, matched on age, sex and left atrial dilation. The two groups had similar baseline parameters. LB procedures were significantly shorter than RFA (129 (110-160) vs. 160 (119-198) min, p = 0.007). During AF ablation, two major complications occurred in each group. At the one-year follow-up, AF recurrence was diagnosed in 7 (14%) of the LB group vs. 14 (28%) of the RFA group (p = 0.14). Moreover, we observed that third-generation LB procedures were associated with shorter laser applications (22 (19-29) vs. 69 (55-76) min, p < 0.001) and procedural durations (111 (100-128) vs. 151.5 (128.5-167) min, p < 0.001) compared to second-generation LB procedures. In the context of the major increase in the number of AF ablations, LB demonstrated consistent results in terms of clinical success, complications and also reduced procedure durations compared to RFA.

Cardiac stereotactic ablative radiotherapy for refractory ventricular arrhythmias: A radical alternative? A narrative review of rationale and cardiological aspects.

Ventricular arrhythmias are serious life-threatening cardiac disorders. Despite many technological improvements, a non-negligible number of patients present refractory ventricular tachycardias, resistant to a catheter ablation procedure, placing these patients in a therapeutic impasse. Recently, a cardiac stereotactic radioablative technique has been developed to treat patients with refractory ventricular arrhythmias, as a bail out strategy. This new therapeutic option historically brings together two fields of expertise unknown to each other, pointing out the necessity of an optimal partnership between cardiologists and radiation oncologists. As described in this narrative review, the understanding of cardiological aspects of the technique for radiation oncologists and treatment technical aspects comprehension for cardiologists represent a major challenge for the application and the future development of this promising treatment.

Running after Activated Clotting Time Values in Patients Receiving Direct Oral Anticoagulants: A Potentially Dangerous Race. Results from a Prospective Study in Atrial Fibrillation Catheter Ablation Procedures.

BACKGROUND: Activated Clotting Time (ACT) guided heparinization is the gold standard for titrating unfractionated heparin (UFH) administration during atrial fibrillation (AF) ablation procedures. The current ACT target (300 s) is based on studies in patients receiving a vitamin K antagonist (VKA). Several studies have shown that in patients receiving Direct Oral Anticoagulants (DOACs), the correlation between ACT values and UFH delivered dose is weak. OBJECTIVE: To assess the relationship between ACT and real heparin anticoagulant effect measured by anti-Xa activity in patients receiving different anticoagulant treatments. METHODS: Patients referred for AF catheter ablation in our centre were prospectively included depending on their anticoagulant type. RESULTS: 113 patients were included, receiving rivaroxaban (n = 30), apixaban (n = 30), dabigatran (n = 30), and VKA (n = 23). To meet target ACT, a higher UFH dose was required in DOAC than VKA patients (14,077.8 IU vs. 9565.2 IU, p < 0.001), leading to a longer time to achieve target ACT (46.5 min vs. 27.3 min, p = 0.001). The correlation of ACT and anti-Xa activity was tighter in the VKA group (Spearman correlation ρ = 0.53), compared to the DOAC group (ρ = 0.19). Despite lower ACT values in the DOAC group, this group demonstrated a higher mean anti-Xa activity compared to the VKA group (1.56 ± 0.39 vs. 1.14 ± 0.36; p = 0.002). CONCLUSION: Use of a conventional ACT threshold at 300 s during AF ablation procedures leads to a significant increase in UFH administration in patients treated with DOACs. This increase corresponds more likely to an overdosing than a real increase in UFH requirement.

Distance between the descending aorta and the left inferior pulmonary vein as a determinant of biophysical parameters during paroxysmal atrial fibrillation cryoablation.

INTRODUCTION: The distance from the descending aorta (DA) to the posterior wall of the left atrium (LA) is variable. We aimed to determine whether the proximity between the DA and the left inferior pulmonary vein (LIPV) ostium has an impact on biophysical parameters and cryoballoon (CB) ablation efficacy during LIPV freezing. METHODS: Patients referred for CB-ablation of atrial fibrillation (AF) in two high-volume centers were included. Cryoablation data were collected prospectively for each patient. The anatomical relationships between the LIPV and the DA (distance LIPV ostium-DA, presence of an aortic imprint on the posterior aspect of the LIPV) were then retrospectively analysed on the LA computed tomography scans realized before AF ablation. RESULTS: A total of 350 patients were included (70% men, 59.7 ± 11.5 years). The decrease in the Ostium-DA distance was significantly correlated to the increase in the time-to-isolation (TTI) (r = -.31; p = .036), with less negative temperature (r = -.11; p = .045). Similarly, the presence of an aortic imprint on the LIPV was associated with a longer TTI (p < .001). The analysis of redo procedures data shows a trend toward the presence of shorter ostium-DA distances (15.3 ± 3.29 vs. 18.1 ± 4.99, p = .15) and more frequent aortic imprints (63.6% vs. 47.5%, p = .34) in patients with LIPV reconnection as opposed to patients without reconnection in the LIPV. CONCLUSION: Our findings indicated that the DA seems to have a "radiator" effect influencing LIPV cryoablation parameters during CB-ablation. Additional studies will be needed to elucidate whether this biophysical influence has a clinical impact in LIPVs reconnections.

Mechanism of ventricular tachycardia in a patient with double-outlet left ventricle.

We report the case of ventricular tachycardia (VT) ablation procedure in a patient with history of surgically repaired double-outlet left ventricle. The electrophysiology procedure revealed a re-entry pattern between the right-ventricle to main-pulmonary-artery conduit and the tricuspid annulus. The re-entrant mechanism was most likely promoted by a fibrous remodeling of this area, related to the surgical repair. This case is the first to describe a re-entry mechanism between fixed anatomical barriers in a repaired right ventricle of a double-outlet left ventricle. A pace mapping technique was used to highlight the VT isthmus.

Is There an Association between Epicardial Adipose Tissue and Outcomes after Paroxysmal Atrial Fibrillation Catheter Ablation?

BACKGROUND: In patients undergoing paroxysmal atrial fibrillation (PAF) ablation, pulmonary vein isolation (PVI) alone fails in maintaining sinus rhythm in up to one third of patients after a first catheter ablation. Epicardial adipose tissue (EAT), as an endocrine-active organ, could play a role in the recurrence of AF after catheter ablation. OBJECTIVE: To evaluate the predictive value of clinical, echocardiographic, biological parameters and epicardial fat density measured by computed tomography scan (CT-scan) on AF recurrence in PAF patients who underwent a first pulmonary vein isolation procedure using radiofrequency (RF). METHODS: This monocentric retrospective study included all patients undergoing first-time RF PAF ablation at the Nancy University Hospital between March 2015 and December 2018 with one-year follow-up. RESULTS: 389 patients were included, of whom 128 (32.9%) had AF recurrence at one-year follow-up. Neither total-EAT volume (88.6 ± 37.2 cm3 vs. 91.4 ± 40.5 cm3, p = 0.519), nor total-EAT radiodensity (-98.8 ± 4.1 HU vs. -98.8 ± 3.8 HU, p = 0.892) and left atrium-EAT radiodensity (-93.7 ± 4.3 HU vs. -93.4 ± 6.0 HU, p = 0.556) were significantly associated with AF recurrence after PAF ablation. In multivariate analysis, previous cavo-tricuspid isthmus (CTI) ablation, ablation procedure duration, BNP and triglyceride levels remained independently associated with AF recurrence after catheter ablation at 12-months follow-up. CONCLUSION: Contrary to persistent AF, EAT parameters are not associated with AF recurrence after paroxysmal AF ablation. Thus, the role of the metabolic atrial substrate in PAF pathophysiology appears less obvious than in persistent AF.

Impact of Midregional N-Terminal Pro-Atrial Natriuretic Peptide and Soluble Suppression of Tumorigenicity 2 Levels on Heart Rhythm in Patients Treated With Catheter Ablation for Atrial Fibrillation: The Biorhythm Study.

Background We assessed the impact of preprocedural plasma levels of MRproANP (midregional N-terminal pro-atrial natriuretic peptide) and sST2 (soluble suppression of tumorigenicity 2) on recurrence of atrial fibrillation (AF) at 1 year after catheter ablation of AF. Methods and Results This was a prospective, multicenter, observational study including patients undergoing catheter ablation of AF. MRproANP and sST2 were measured in a peripheral venous blood preprocedure, and MRproANP was assessed in the right and left atrial blood during ablation. The primary end point was recurrent AF between 3 and 12 months postablation, defined as a documented (>30 seconds) episode of AF, flutter, or atrial tachycardia. We included 106 patients from December 2017 to March 2019; 105 had complete follow-up, and the mean age was 63 years with 74.2% males. Overall, 34 patients (32.1%) had recurrent AF. In peripheral venous blood, MRproANP was significantly higher in patients with recurrent AF (median, 192.2; [quartile 1-quartile 3, 155.9-263.9] versus 97.1 [60.9-150.7] pmol/L; P<0.0001), as was sST2 (median, 30.3 [quartile 1-quartile 3, 23.3-39.3] versus 23.4 [95% CI, 17.4-33.0] ng/mL; P=0.0033). In the atria, MRproANP was significantly higher than in peripheral blood and was higher during AF than during sinus rhythm. Receiver operating characteristic curve analysis identified a threshold of MRproANP>107.9 pmol/L to predict AF recurrence at 1 year and a threshold of >26.7 ng/mL for sST2. By multivariate analysis, MRproANP>107.9 pmol/L was the only independent predictor of recurrent AF (OR, 24.27; 95% CI, 4.23-139.18). MRproANP<107.9 pmol/L identified subjects at very low risk of recurrence (negative predictive value >95%). Conclusions Elevated MRproANP level independently predicts recurrent AF, whereas sST2 levels do not appear to have any prognostic value in assessing the risk of recurrence of AF up to 1 year after catheter ablation. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03351816.

New Perspective in Atrial Fibrillation.

Despite a large number of publications on this subject, the pathophysiological mechanisms involved in atrial fibrillation (AF) onset and recurrence are uncertain [...].

Low versus standard-blood-flow reperfusion strategy in a pig model of refractory cardiac arrest resuscitated with Extra Corporeal Membrane Oxygenation.

OBJECTIVE: This study was designed to assess the effect of two veno-arterial ExtraCorporeal Membrane Oxygenation (ECMO) blood-flow strategies in an experimental model of Extracorporeal Cardio-Pulmonary Resuscitation (ECPR) on macrocirculatory, metabolic and microcirculatory parameters in the first six hours of ECMO initiation. METHODS: Cardiac arrest was induced in 18 pigs by surgical ligature of the left descending coronary artery followed by a low-flow time of 40 min using internal cardiac massage. ECPR was initiated in normothermia with an ECMO blood flow of 30-35 ml.kg-1. min-1 (low-blood-flow group, LBF) or 65-70 ml.kg-1. min-1 (standard-blood-flow group, SBF), with the same mean arterial pressure target of 65 mmHg adjusted with norepinephrine. Macrocirculatory and metabolic parameters were assessed by lactate clearance and carotid blood flow. Microcirculatory parameters were assessed by sublingual microcirculation with Sidestream Dark Field (SDF) imaging and peripheral Near-InfraRed Spectrometry (NIRS). Inflammatory cytokine levels were measured with a multicomplexed ELISA-based array platform. RESULTS: There were no between-group differences at baseline and at ECMO initiation (H0). Lactate clearance at H6 was lower in LBF compared to SBF (6.67[-10.43-18.78] vs. 47.41[19.54-70.69] %, p = 0.04). Carotid blood flow was significantly lower (p<0.005) during the last four hours despite similar mean arterial pressure levels. For microvascular parameters, SDF and NIRS parameters were transitorily impaired at H3 in LBF. IL-6 cytokine level was significantly higher in LBF at the end of the experiment. CONCLUSION: In an experimental porcine model of refractory cardiac arrest treated by ECMO, a low-blood-flow strategy during the first six hours of resuscitation was associated with lower lactate clearance and lower cerebral blood flow with no benefits on ischemia-reperfusion parameters.

Impact of Global and Segmental Hypertrophy on Two-Dimensional Strain Derived from Three-Dimensional Echocardiography in Hypertrophic Cardiomyopathy: Comparison with Healthy Subjects.

BACKGROUND: Patients with hypertrophic cardiomyopathy (HCM) present unusual myocardial mechanics. The aim of this study was to assess the impact of hypertrophy on global and regional two-dimensional (2D) strain derived from both tomographic images (2D/2D) and volumetric image acquisition (2D/three-dimensional [3D]) in patients with HCM compared with control subjects. METHODS: Comprehensive resting 2D and 3D echocardiography was performed in 40 patients with HCM and in 53 control subjects, with comparable distributions of age, gender, and left ventricular (LV) ejection fraction. LV global and segmental measurements of all 2D/2D and 2D/3D peak strain components (global and segmental longitudinal strain, global and segmental circumferential strain, global and segmental radial strain, and global and segmental area strain) and 3D indexed LV end-diastolic myocardial mass were obtained from all patients. LV wall thickness was assessed in short-axis views and classified in four quartiles (<10.5, 10.5-13.0, 13.0-16.5, and >16.5 mm). RESULTS: The reproducibility of 2D/3D strain was similar or greater and more consistent for all components compared with 2D/2D strain analysis. There was a significant correlation between 3D LV end-diastolic mass and all 2D/3D strain components (P < .05). Two-dimensional/3D global circumferential strain had the strongest association with 3D LV ejection fraction (r = 0.50, P = .001). For segmental deformation, patients with HCM had lower longitudinal deformation whatever the LV wall thickness, whereas circumferential function was increased in nonhypertrophied and poorly hypertrophied segments compared with control subjects. CONCLUSIONS: Two-dimensional/3D strain is a reliable technique to assess myocardial deformation. Myocardial mass is related to 2D/3D strain components in patients with HCM. Circumferential deformation, compared with longitudinal deformation, seems to be the main component of the maintenance of systolic function in HCM.