Significant Systolic Anterior Motion Research Articles

Systolic anterior motion of the anterior mitral valve leaflet begins in subclinical hypertrophic cardiomyopathy.

Anterior mitral valve leaflet (AMVL) elongation is detectable in overt and subclinical hypertrophic cardiomyopathy (HCM). We sought to investigate the dynamic motion of the aorto-mitral apparatus to understand the behaviour of the AMVL and the mechanisms of left ventricular outflow tract obstruction (LVOTO) predisposition in HCM. Cardiovascular magnetic resonance imaging using a 1.5 Tesla scanner was performed on 36 HCM sarcomere gene mutation carriers without left ventricular hypertrophy (G+LVH-), 31 HCM patients with preserved ejection fraction carrying a pathogenic sarcomere gene mutation (G+LVH+), and 53 age-, sex-, and body surface area-matched healthy volunteers. Dynamic excursion of the aorto-mitral apparatus was assessed semi-automatically on breath-held three-chamber cine steady-state free precession images. Four pre-defined regions of interest (ROIs) were tracked: ROIPMVL: hinge point of the posterior mitral valve leaflet; ROITRIG: intertrigonal mitral annulus; ROIAMVL: AMVL tip; and ROIAAO: anterior aortic annulus. Compared with controls, normalized two-dimensional displacement-vs.-time plots in G+LVH- revealed subtle but significant systolic anterior motion (SAM) of the AMVL (P < 0.0001) and reduced longitudinal excursion of ROIAAO (P = 0.014) and ROIPMVL (P = 0.048). In overt and subclinical HCM, excursion of the ROITRIG/AMVL/PMVL was positively associated with the burden of left ventricular fibrosis (P < 0.028). As expected, SAM was observed in G+LVH+ together with reduced longitudinal excursion of ROITRIG (P = 0.049) and ROIAAO (P = 0.008). Dyskinesia of the aorto-mitral apparatus, including SAM of the elongated AMVL, is detectable in subclinical HCM before the development of LVH or left atrial enlargement. These data have the potential to improve our understanding of early phenotype development and LVOTO predisposition in HCM.

Hypertrophic Obstructive Cardiomyopathy Associated with Moderate Aortic Stenosis in Symptomatic 75-Year-Old Female: A Case Report

A 72-year-old female was found to have symptomatic hypertrophic obstructive cardiomyopathy associated with significant aortic stenosis. She was found to have severe left ventricular outflow tract obstruction, asymmetric septal hypertrophy, significant systolic anterior motion of the anterior mitral valve leaflet, and mitral regurgitation. She was also found to have moderate aortic stenosis that made the obstruction even worse which made the patient progressively symptomatic not responding to medical therapy. She eventually underwent cardiac surgery in form of left ventricular septal myomectomy and bioprosthetic aortic valve replacement (tissue AVR) with a size 23 tissue valve, aortic root enlargement with bovine pericardial patch. She is currently stable on optimal medical therapy, feels much better and stable cardiac-wise with much better quality of life.

Combined ablation for paroxysmal atrial fibrillation and drug-refractory hypertrophic obstructive cardiomyopathy: a case report.

BackgroundHypertrophic obstructive cardiomyopathy (HOCM) is sometimes concomitant with atrial fibrillation (AF) and exacerbates heart failure symptoms. Although optimal medication for the reduction of left ventricular outflow tract (LVOT) obstruction and the maintenance of sinus rhythm should be considered, it is difficult to control the symptoms permanently.Case summaryA 45-year-old man, diagnosed with HOCM, presented with progressive dyspnoea on exertion, which significantly deteriorated during episodes of paroxysmal AF, despite optimal medical therapy. On echocardiography, we found LVOT obstruction with a peak pressure gradient of 98 mmHg, concomitant with redundant mitral valve leaflets, which caused significant systolic anterior motion (SAM). Since he declined open surgery, we selected a combination of catheter interventions, AF ablation, and alcohol septal ablation (ASA). After the AF ablation, the occurrence of AF significantly decreased, and there was no recurrence after the ASA. By 6 months, the plasma N-terminal pro-B-type natriuretic peptide level had decreased from 1022 to 124 pg/mL, the peak pressure gradient of LVOT decreased from 98 to 12 mmHg, and the left atrium volume decreased from 203 to 178.4 mL. The improvement in the SAM was visualized on echocardiography and was haemodynamically corroborated by the four-dimensional (4D)-flow cardiac magnetic resonance (CMR).DiscussionThe treatment of drug-refractory HOCM concomitant with paroxysmal AF needs both septal reduction and the maintenance of sinus rhythm, which can be accomplished through transcatheter interventions. Moreover, the detailed intra-ventricular haemodynamic assessment in HOCM patients can be explored using the 4D-flow CMR.

Exercise Echocardiography following Septal Myectomy for Hypertrophic Obstructive Cardiomyopathy.

To investigate outcome after septal myectomy and to evaluate long-term hemodynamics with exercise echocardiography. This study included 40 consecutive patients operated with septal myectomy for hypertrophic obstructive cardiomyopathy from January 1998 to August 2017 at Skane University Hospital, Lund, Sweden. Perioperative clinical data and echocardiography measurements were reviewed retrospectively. Patients (n = 36) who were alive and living in Sweden were invited for exercise echocardiography to evaluate exercise capacity and hemodynamics, of whom 19 patients performed exercise echocardiography. Overall survival was 100% at 1 year and 96% at 5 years following surgery. Preoperative median resting peak LVOT (left ventricular outflow tract) gradient was 80 mm Hg. Septum thickness was reduced from 22 ± 4 mm preoperatively to 16 ± 3 mm postoperatively (p < 0.001). During exercise echocardiography, the peak LVOT gradient was 8 mm Hg at rest, and increased to 13 mm Hg during exercise echocardiography (p = 0.002). None of the patients had dynamic LVOT obstruction during exercise echocardiography, and there was no clinically significant systolic anterior motion or severe mitral insufficiency during exercise. Long-term survival following septal myectomy is very good. At long-term follow-up, LVOT gradients were low and exercise echocardiography demonstrated good hemodynamics.

Isolated septal myectomy for hypertrophic obstructive cardiomyopathy: an update on the Toronto General Hospital experience

Isolated septal myectomy is considered the gold standard for refractory left ventricular outflow tract (LVOT) obstruction at centers with dedicated hypertrophic obstructive cardiomyopathy (HOCM) surgeons. In this paper, we provide an update on the Toronto General Hospital (TGH) experience for isolated septal myectomy and comment on the safety and efficacy of myectomy in patients with thin basal septal thickness at our institution. We retrospectively reviewed all patients undergoing surgical myectomy at our institution from January 2012 to August 2016. We analyzed patient characteristics, intraoperative variables, pre- and post-procedural echocardiographic parameters, and key outcomes including post-operative stroke, renal failure, iatrogenic ventricular septal defect (VSD), post-procedure insertion of permanent pacemaker, and mortality. At our institution, 150 isolated septal myectomy surgeries were performed over the study period. Preoperative echocardiography demonstrated an average basal septal thickness of 2.10±0.43 cm with a resting gradient of 67±37 mmHg and a provoked gradient of 89±40 mmHg. Fifty percent of patients had significant systolic anterior motion (SAM) of their mitral valve and 53% had associated moderate to severe mitral regurgitation (MR). Of note, 24% of patients had a thin septum of ≤1.7 cm. Discharge echocardiograms demonstrated significant septal reduction to an average basal septal thickness of 1.04±0.26 (P<0.05), with negligible resting and provokable LVOT gradients. At the time of discharge, none of the patients had significant SAM and only 5.3% of patients had residual greater than mild MR. Patients undergoing isolated myectomy with a thin basal septum had similar outcomes to those with a >1.7 cm septal thickness. In our contemporary cohort, there were no iatrogenic VSDs, 5.3% of patients required a permanent pacemaker and there was one early death. Our cohort demonstrates that isolated septal myectomy remains a safe and effective operation that can achieve excellent results, irrespective of basal septal thickness, when done by experienced surgeons in a dedicated hypertrophic cardiomyopathy (HCM) center.

Technical aspects of mitral valve repair in Barlow's valve with prolapse of both leaflets: triangular resection for excess tissue, sophisticated chordal replacement, and their combination (the restoration technique).

Histological degeneration in Barlow's valve mainly starts in the rough zone, frequently expands toward the chordae, and advances to the clear zone, resulting in a saccular aneurysm-like morphology in the prolapsed region. On this basis, we have repaired the prolapsed segment by triangular resection, chordal replacement and the combination (the restoration technique). The aim of this study was to report our initial findings and evaluate the efficacy of our technique. Twelve patients diagnosed with Barlow's valve with prolapse of both leaflets (5 women; mean age, 49years) underwent the restoration technique between January 2008 and March 2013. We retrospectively reviewed short-term clinical outcomes. The mean duration of the clinical follow-up was 2.5±1.7years. The restoration technique was successfully performed in all patients. Predominant repair techniques were isolated triangular resection (anterior 8, posterior 9), a combination of triangular resection with chordal replacement (anterior 1, posterior 1), and isolated chordal replacement (anterior 3, posterior 1). All patients underwent complete mitral annuloplasty, and the mean ring size was 31±2mm. In-hospital mortality was not noted. Late transthoracic echocardiography showed no or trace mitral regurgitation without significant systolic anterior motion in all patients. The New York Heart Association functional class was significantly improved from 1.3±0.5 before surgery to 1.0±0.0 after it (p<0.01). There were no late thromboembolic or bleeding events. Initial experience with the restoration technique has provided excellent results without significant systolic anterior motion. Our technique may contribute to improve late results in Barlow's valve.

Alfieri Repair for Post-Repair Mitral Systolic Anterior Motion in a Young Child

An 11-year-old patient with Marfan syndrome presented with severe mitral and tricuspid regurgitation and underwent mitral valve repair consisting of a vertical folding plasty of a redundant and prolapsing A1, closure of a deep cleft-like A1-A2 indentation, and annuloplasty to 28 mm, and tricuspid valve repair. Post-bypass echocardiography showed significant systolic anterior motion of the mitral valve. The annuloplasty was upsized to 34 mm and the A1 folding plasty taken down. Echocardiography showed persistent systolic anterior motion. An edge-to-edge repair was placed at A1-P1, eliminating all systolic anterior motion. The patient had an uneventful postoperative course and 6-week follow-up.

Robotic Posterior Mitral Leaflet Repair: Neochordal Versus Resectional Techniques

Resectional techniques are the established method of posterior mitral valve leaflet repair for degenerative disease; however, use of neochordae in a robotically assisted approach is gaining acceptance because of its versatility for difficult multisegment disease. The purposes of this study were to compare the versatility, safety, and effectiveness of neochordal versus resectional techniques for robotic posterior mitral leaflet repair. From December 2007 to July 2010, 334 patients underwent robotic posterior mitral leaflet repair for degenerative disease by a resectional (n = 248) or neochordal (n = 86) technique. Outcomes were compared both unadjusted and after propensity score matching. Neochordae were more likely to be used than resection in patients with two (28% versus 13%; p = 0.002) or three (3.7% versus 0.87%; p = 0.08) diseased posterior leaflet segments. Three resection patients (0.98%) but no neochordal patient required reoperation for hemodynamically significant systolic anterior motion. Residual mitral regurgitation (MR) at hospital discharge was similar for matched neochordal versus resection patients (MR 0+, 82% versus 89%; MR 1+, 14% versus 8.2%; MR 2+, 2.3% versus 2.6%; 1 neochordal patient had 4+ MR and underwent reoperation; p = 0.14). Among matched patients, postoperative mortality and morbidity were similarly low. Compared with a resectional technique, robotic posterior mitral leaflet repair with neochordae is associated with shorter operative times and no occurrence of systolic anterior motion. The versatility, effectiveness, and safety of this repair make it a good choice for patients with advanced multisegment disease.

Outcome of Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy in Children and Young Adults

Obstructive hypertrophic cardiomyopathy (HCM) is an important cause of heart failure in children, but there are limited data addressing outcome of myectomy in children. Our objective was to evaluate the early and late results of septal myectomy in pediatric HCM. We reviewed 127 consecutive patients (62% male) who underwent transaortic septal myectomy for obstructive HCM from January 1975 to December 2010 at 21 or less years of age. Mean age at operation was 12.9 ± 5.5 years. Preoperatively, mean maximum instantaneous gradient was 89 mm Hg and 95% had significant systolic anterior motion (SAM) with mitral regurgitation (MR). Implantable cardioverter defibrillator (ICD) and permanent pacemaker prior to surgery was present in 21 patients (17%) and 15 (11.7%), respectively. Transaortic extended left ventricular septal myectomy was performed in all patients with no early deaths. Iatrogenic morbidity included new aortic valve regurgitation requiring repair in 7 (5.5%), mitral regurgitation needing repair in 2 (1.5%), ventricular septal defect in 1 (1%), and heart block requiring permanent pacemaker in 1 (1%). An ICD was implanted postoperatively in 8 during the same hospital admission. Mean MIG decreased from 89 to 6 mm Hg (p < 0.0001). Postoperatively, residual chordal SAM was present in 23% with mild or no MR; moderate MR was detected in 1 patient. Four patients (3%) died late during the mean follow-up period of 8.3 years (maximum, 37 years); 1 death was sudden. Overall survival was 98.6%, 94.9%, 92.4%, and 92.4% at 5, 10, 15, and 20 years, respectively. Freedom from any cardiac reoperation was 91.2%, 87.8%, 78.7%, and 72.7% at 5, 10, 15, and 20 years, respectively. Repeat septal myectomy was performed in 6 patients (5%). At late follow-up, 95% were in New York Heart Association functional class I or II and 25 patients underwent late ICD placement. Septal myectomy is safe and effective in children with obstructive HCM, but limited exposure may increase risk of aortic or mitral valve injury. Late survival is better than the previously published untreated natural history of HCM. Patient selection and surgical expertise remain critical components of septal myectomy, especially before considering a prophylactic myectomy in a seemingly asymptomatic patient.

Initial experience with the Cosgrove-Edwards annuloplasty system

The mitral valve has a nonplanar shape and a sphincter action. Pathologic dilatation occurs along the posterior annulus. To preserve the physiologic function and correct annular dilatation, we developed an annuloplasty system that is universally flexible and produces a measured plication of the posterior annulus (Cosgrove-Edwards Annuloplasty System). The results of 150 consecutive mitral valve repairs using this system were analyzed. Mean age was 58 +/- 13 years; 59% were men. The cause of the valve disease was degenerative in 75% of the patients, rheumatic in 13%, ischemic in 8%, and infectious in 4%. Associated procedures were performed in 61 patients (41%). Echocardiographic mitral regurgitation decreased from 3.7 +/- 0.6 before repair to 0.2 +/- 0.4 after repair (p < 0.0001). There were no hospital deaths and no cases of hemodynamically significant systolic anterior motion or other annuloplasty-related complications. Follow-up was 100% complete at a mean of 3.1 +/- 3.6 months. There were three late deaths, three transient ischemic attacks, and one episode of endocarditis. Five patients (3.3%) have undergone reoperation for recurrent mitral insufficiency; no reoperations were related to the annuloplasty system. At a mean of 9 months, three-dimensional reconstruction of the mitral annulus from multiple echocardiographic images confirmed the nonplanar shape and sphincter mechanism of the annulus. Annular orifice area decreased 19% during the cardiac cycle from a mean of 10.3 cm2 in diastole to 8.6 cm2 in systole. This annuloplasty system is effective for repair of insufficiency secondary to all causes, preserves physiologic annulus function, and is associated with a low incidence of valve-related complication.