Left ventricular remodeling and mitral valve surgery: Prospective study with real-time 3-dimensional echocardiography and speckle tracking

Cardiac reverse remodeling in primary mitral regurgitation: mitral valve replacement vs. mitral valve repair

BACKGROUND

When feasible, guidelines recommend mitral valve repair (MVr) over mitral valve replacement (MVR) to treat primary mitral regurgitation (MR), based upon historic outcome studies and transthoracic echocardiography (TTE) reverse remodeling studies. Cardiovascular magnetic resonance (CMR) offers reference standard biventricular assessment with superior MR quantification compared to TTE. Using serial CMR in primary MR patients, we aimed to investigate cardiac reverse remodeling and residual MR post-MVr vs MVR with chordal preservation.

METHODS

83 patients with ≥ moderate-severe MR on TTE were prospectively recruited. 6-min walk tests (6MWT) and CMR imaging including cine imaging, aortic/pulmonary through-plane phase contrast imaging, T1 maps and late-gadolinium-enhanced (LGE) imaging were performed at baseline and 6 months after mitral surgery or watchful waiting (control group).

RESULTS

72 patients completed follow-up (Controls = 20, MVr = 30 and MVR = 22). Surgical groups demonstrated comparable baseline cardiac indices and co-morbidities. At 6-months, MVr and MVR groups demonstrated comparable improvements in 6MWT distances (+ 57 ± 54 m vs + 64 ± 76 m respectively, p = 1), reduced indexed left ventricular end-diastolic volumes (LVEDVi; - 29 ± 21 ml/m2 vs - 37 ± 22 ml/m2 respectively, p = 0.584) and left atrial volumes (- 23 ± 30 ml/m2 and - 39 ± 26 ml/m2 respectively, p = 0.545). At 6-months, compared with controls, right ventricular ejection fraction was poorer post-MVr (47 ± 6.1% vs 53 ± 8.0% respectively, p = 0.01) compared to post-MVR (50 ± 5.7% vs 53 ± 8.0% respectively, p = 0.698). MVR resulted in lower residual MR-regurgitant fraction (RF) than MVr (12 ± 8.0% vs 21 ± 11% respectively, p = 0.022). Baseline and follow-up indices of diffuse and focal myocardial fibrosis (Native T1 relaxation times, extra-cellular volume and quantified LGE respectively) were comparable between groups. Stepwise multiple linear regression of indexed variables in the surgical groups demonstrated baseline indexed mitral regurgitant volume as the sole multivariate predictor of left ventricular (LV) end-diastolic reverse remodelling, baseline LVEDVi as the most significant independent multivariate predictor of follow-up LVEDVi, baseline indexed LV end-systolic volume as the sole multivariate predictor of follow-up LV ejection fraction and undergoing MVR (vs MVr) as the most significant (p < 0.001) baseline multivariate predictor of lower residual MR.

CONCLUSION

In primary MR, MVR with chordal preservation may offer comparable cardiac reverse remodeling and functional benefits at 6-months when compared to MVr. Larger, multicenter CMR studies are required, which if the findings are confirmed could impact future surgical practice.

Late plasma exosome microRNA-21-5p depicts magnitude of reverse ventricular remodeling after early surgical repair of primary mitral valve regurgitation

Introduction

Primary mitral valve regurgitation (MR) results from degeneration of mitral valve apparatus. Mechanisms leading to incomplete postoperative left ventricular (LV) reverse remodeling (Rev-Rem) despite timely and successful surgical mitral valve repair (MVR) remain unknown. Plasma exosomes (pEXOs) are smallest nanovesicles exerting early postoperative cardioprotection. We hypothesized that late plasma exosomal microRNAs (miRs) contribute to Rev-Rem during the late postoperative period.

Methods

Primary MR patients (n = 19; age, 45-71 years) underwent cardiac magnetic resonance imaging and blood sampling before (T0) and 6 months after (T1) MVR. The postoperative LV Rev-Rem was assessed in terms of a decrease in LV end-diastolic volume and patients were stratified into high (HiR-REM) and low (LoR-REM) LV Rev-Rem subgroups. Isolated pEXOs were quantified by nanoparticle tracking analysis. Exosomal microRNA (miR)-1, -21-5p, -133a, and -208a levels were measured by RT-qPCR. Anti-hypertrophic effects of pEXOs were tested in HL-1 cardiomyocytes cultured with angiotensin II (AngII, 1 μM for 48 h).

Results

Surgery zeroed out volume regurgitation in all patients. Although preoperative pEXOs were similar in both groups, pEXO levels increased after MVR in HiR-REM patients (+0.75-fold, p = 0.016), who showed lower cardiac mass index (-11%, p = 0.032). Postoperative exosomal miR-21-5p values of HiR-REM patients were higher than other groups (p < 0.05). In vitro, T1-pEXOs isolated from LoR-REM patients boosted the AngII-induced cardiomyocyte hypertrophy, but not postoperative exosomes of HiR-REM. This adaptive effect was counteracted by miR-21-5p inhibition.

Summary/Conclusion

High levels of miR-21-5p-enriched pEXOs during the late postoperative period depict higher LV Rev-Rem after MVR. miR-21-5p-enriched pEXOs may be helpful to predict and to treat incomplete LV Rev-Rem after successful early surgical MVR.

Perioperative management of patients with prosthetic heart valves-A narrative review

Worldwide, about 13% of the 200,000 annual recipients of prosthetic heart valves (PHV) present for various surgical procedures. Also, more and more females are opting for pregnancies after having PHV. All patients with PHV present unique challenges for the anesthesiologists, surgeons and obstetricians (in case of deliveries). They have to deal with the perioperative management of anticoagulation and a host of other issues involved. We reviewed the English language medical literature relevant to the different aspects of perioperative management of patients with PHV, particularly the guidelines of reputed societies that appeared in the last 20 years. Regression of cardiac pathophysiology following valve replacement is variable both in extent and timeline. The extent to which reverse remodeling occurs depends on the perioperative status of the heart. We discussed the perioperative assessment of patients with PHV, including focused history and relevant investigations with the inferences drawn. We examined the need for prophylaxis against infective endocarditis and management of anticoagulation in such patients in the perioperative period and the guidelines of reputed societies. We also reviewed the conduct of anesthesia, including general and regional anesthesia (neuraxial and peripheral nerve/plexus blocks) in such patients. Finally, we discussed the management of delivery in this group of high-risk patients. From the discussion of different aspects of perioperative management of patients with PHV, we hope to guide in formulating the comprehensive plan of management of safe anesthesia in such patients.

Stage-based approach to predict left ventricular reverse remodeling after mitral repair

Background

Although predictors of reverse left ventricular (LV) remodeling postmitral valve repair are critical for guiding perioperative decision‐making, there remains a paucity of randomized, prospective data to support the criteria that potential predictor variables must meet.

Methods and Results

The CAMRA CardioLink‐2 randomized trial allocated 104 patients to either leaflet resection or preservation strategies for mitral repair. The correlation of indexed left ventricular end‐systolic volume (LVESVI), indexed left ventricular end‐diastolic volume (LVEDVI), and left ventricular ejection fraction (LVEF) were tested with univariate analysis and subsequently with multivariate analysis to determine independent predictors of reverse remodeling at discharge and at 12 months postoperatively. At discharge, both LVESVI and LVEDVI were independently associated with their preoperative values (p < .001 for both) and LVEF by preoperative LVESVI (p < .001). Mitral ring size was favorably associated with the change in LVESVI (p < .05) and LVEF (p < .01) from predischarge to 12 months, while the mean mitral valve gradient after repair was adversely associated with the change in LVESVI (p < .05) and LVEDVI (p < .05). No significant associations were found between reverse remodeling and coaptation height nor mitral repair technique.

Conclusions

Beyond confirming the lack of impact of mitral repair technique on reverse remodeling, this investigation suggests that recommending surgery before significant LV dilatation or dysfunction, as well as higher postoperative mitral valve hemodynamic performance, may enhance remodeling capacity following mitral repair.

Changes in renin-angiotensin-aldosterone system during cardiac remodeling after mitral valvuloplasty in dogs

BACKGROUND

Information regarding changes in renin-angiotensin-aldosterone system (RAAS) during cardiac remodeling after mitral valvuloplasty (MVP) in dogs remains lacking.

HYPOTHESIS/OBJECTIVES

To assess the longitudinal effects of MVP on circulating RAAS activity.

ANIMALS

Eight client-owned dogs receiving MVP for myxomatous mitral valve disease (MMVD).

METHODS

This is a cohort study. Plasma renin activity (PRA), angiotensin II (AT2), aldosterone (PAC), blood urea nitrogen (BUN), and creatinine concentrations, were measured in these dogs before (baseline) and at 3 consecutive monthly follow-ups (Post-1M, Post-2M, Post-3M). Echocardiography was concomitantly used to assess the process of cardiac recovery after MVP.

RESULTS

The echocardiography revealed a significant decrease in LVIDDN, LA/Ao, FS, E velocity, E/A, E' sep, S' lat, E' lat, and A' lat after MVP compared with baseline (P < .05). There was a significant reduction in the PRA (2.45, 3.05, 2.74 vs 8.8 ng/mL/h; P = .002), AT2 (466, 315, 235 vs 1200 pg/mL; P = .009), and PAC (39.88, 47, 54.62 vs 179.5 pg/mL; P = .01), respectively at Post-1M, Post-2M, Post-3M compared to the baseline. Additionally, BUN and creatinine concentrations decreased from Post-1M. The RAAS variables showed significant, weak to moderate, relationship with selected echocardiographic variables.

CONCLUSIONS AND CLINICAL IMPORTANCE

Mitral valvuloplasty contributes to decreased RAAS activity in MMVD dogs, which paralleled the process of cardiac reverse remodeling up to Post-3M. This information facilitates formulating strategies to optimize clinical outcomes for dogs after MVP.

Mitral repair with leaflet preservation versus leaflet resection and ventricular reverse remodeling from a randomized trial

OBJECTIVES

In the Canadian Mitral Research Alliance (CAMRA) Trial CardioLink-2 leaflet resection versus preservation techniques for posterior leaflet prolapse was investigated and no difference was shown in their effect on mean mitral gradient at peak exercise at 12 months postoperatively. The purpose of this subanalysis was to evaluate the effect of the 2 strategies on left ventricular (LV) reverse remodeling after repair.

METHODS

A total of 104 patients were randomized to either a leaflet resection or leaflet preservation strategy. Echocardiograms, performed at baseline (preoperative), predischarge, and 12 months postoperatively, were analyzed in a blinded fashion at a core laboratory.

RESULTS

All patients underwent successful mitral repair. At discharge, 3 patients showed moderate mitral regurgitation, whereas the remainder showed mild or less regurgitation. Compared with the baseline echocardiogram, the indexed end diastolic volume was reduced at the discharge echocardiogram (P < .0001) and was further reduced at the 12-month echocardiogram (P = .01). In contrast, the indexed end systolic volume did not significantly change from baseline assessed at the predischarge echocardiogram (P = .32) but improved at 12 months postoperatively (P < .0001), resulting in a corresponding improvement in ejection fraction at 12 months (P < .0001). The type of mitral repair strategy had no significant effect on LV reverse remodeling trends.

CONCLUSIONS

The mitral repair strategies used did not influence postoperative LV reverse remodeling, which occurred in stages. Although LV end diastolic dimensions recovered before discharge, improvements in LV end systolic dimension were evident 12 months after repair.

Safety and performance of a novel transventricular beating heart mitral valve repair system: 1-year outcomes

OBJECTIVES

The objective of this study was to evaluate the safety and performance of a novel, beating heart procedure that enables echocardiographic-guided beating heart implantation of expanded polytetrafluoroethylene (ePTFE) artificial cords on the posterior mitral leaflet of patients with degenerative mitral regurgitation.

METHODS

Two prospective multicentre studies enrolled 13 (first-in-human) and 52 subjects, respectively. Patients were treated with the HARPOON beating heart mitral valve repair system. The primary (30-day) end point was successful implantation of cord(s) with mitral regurgitation reduction to ≤moderate. An independent core laboratory analysed echocardiograms.

RESULTS

Of 65 patients enrolled, 62 (95%) achieved technical success, 2 patients required conversion to open surgery and 1 procedure was terminated. The primary end point was met in 59/65 (91%) patients. Among the 62 treated patients, the mean procedural time was 2.1 ± 0.5 h. Through discharge, there were no deaths, strokes or renal failure events. At 1 year, 2 of the 62 patients died (3%) and 8 (13%) others required reoperations. At 1 year, 98% of the patients with HARPOON cords were in New York Heart Association class I or II, and mitral regurgitation was none/trace in 52% (n = 27), mild in 23% (n = 12), moderate in 23% (n = 12) and severe in 2% (n = 1). Favourable cardiac remodelling outcomes at 1 year included decreased end-diastolic left ventricular volume (153 ± 41 to 119 ± 28 ml) and diameter (53 ± 5 to 47 ± 6 mm), and the mean transmitral gradient was 1.4 ± 0.7 mmHg.

CONCLUSIONS

This initial clinical experience with the HARPOON beating heart mitral valve repair system demonstrates encouraging early safety and performance.

CLINICAL REGISTRATION NUMBERS

NCT02432196 and NCT02768870.

Outcome of mitral valve repair or replacement for non-ischemic mitral regurgitation: a systematic review and meta-analysis

Background

Mitral regurgitation (MR) is a rather common valvular heart disease. The aim of this systematic review and meta-analysis was to compare the outcomes, and complications of mitral valve (MV) replacement with surgical MV repair of non-ischemic MR (NIMR)

Methods

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched until October, 2020. Studies were eligible for inclusion if they included patients with MR and reported early (30-day or in-hospital) or late all-cause mortality. For each study, data on all-cause mortality and incidence of reoperation and operative complications in both groups were used to generate odds ratios (ORs) or hazard ratios (HRs). This study is registered with PROSPERO, CRD42018089608.

Results

The literature search yielded 4834 studies, of which 20 studies, including a total of 21,898 patients with NIMR, were included. The pooled analysis showed that lower age, less female inclusion and incident of hypertension, significantly higher rates of diabetes and atrial fibrillation in the MV replacement group than MV repair group. No significant differences in the rates of pre-operative left ventricle ejection fraction (LVEF) and heart failure were observed between groups. The number of patients in the MV repair group was lower than in the MV replacement group. We found that there were significantly increased risks of mortality associated with replacement of MR. Moreover, the rate of re-operation and post-operative MR in the MV repair group was lower than in the MV replacement group.

Conclusions

In patients with NIMR, MV repair achieves higher survival and leads to fewer complications than surgical MV replacement. In light of these results, we suggest that MV repair surgery should be a priority for NIMR patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01563-2.

Improvement in Left Cardiac Function Following Mitral Valve Repair: Analyses Based on Cardiac Magnetic Resonance Imaging

AIM

This study aimed to evaluate the structural and functional changes of left-sided cardiac chambers by cardiac magnetic resonance imaging (CMRI) in patients with chronic mitral regurgitation after mitral valve repair (MVR).

PATIENTS AND METHODS

Among 103 patients who underwent MVR, 21 showed normal left ventricular (LV) function; their pre- and postoperative left atrial (LA) and LV functions were examined by CMRI.

RESULTS

LV end-diastolic volume, LV end-systolic volume, and LV mass significantly were reduced postoperatively (p<0.01) and postoperative LV ejection fraction tended to decrease. LA volume parameters also significantly decreased postoperatively (p<0.01). The conduit function positively affected the LV filling volume postoperatively (p<0.01); however, no effect on the booster pump function was noted (p=0.01).

CONCLUSION

Restoration of LA and LV functions after a successful MVR was not associated with structural improvement in LA and LV.

Impact of Mitral Surgery for Mitral Regurgitation on Coexisting Aortic Regurgitation

Background: There is no clear finding on the course of coexisting aortic regurgitation (AR) after treatment of mitral regurgitation (MR). We investigated the effect of mitral surgery for MR on coexisting AR.

Methods: Between January 2008 and December 2016, 75 patients underwent mitral surgery for MR coexisting mild AR. Of these, 65 patients who were available to follow-up postoperative echocardiographic tests 1 year after surgery were included in the present study. Patients were divided into two groups according to the degree of postoperative AR. We investigated the predictive factors for continued AR and perioperative cardiac function.

Results: In all, 22 patients’ AR improved and became less than mild and 43 patients’ persisted at mild or increased. The predictive factor for continued AR was left atrial diameter >50 mm (P = 0.021, odds ratio = 4.739, 95% confidence interval: 1.259–17.846) in multivariate logistic regression analysis. No patients underwent reoperation for continued AR in both groups. However, one patient was rehospitalized for heart failure in the continued AR group.

Conclusion: Left atrial diameter may be an important prognostic factor for continued AR after mitral surgery for MR. MR with mild AR should be treated as soon as before the left atrium expands.

Global longitudinal strain: is it a superior assessment method for left ventricular function in patients with chronic mitral regurgitation undergoing mitral valve replacement?

Purpose

Left ventricular ejection fraction may remain normal or even higher despite significant impairment of contractility in cases of mitral regurgitation. The aim of this study is to evaluate the changes in left ventricular function after mitral valve replacement and to study the role of global longitudinal strain in detecting early left ventricular dysfunction using speckle tracking.

Method

Study involved 31 patients who underwent mitral valve replacement for mitral regurgitation. Patient's preoperative and postoperative echocardiography (conventional parameters and global longitudinal strain) and other parameters like functional status, radiological findings, and electrocardiogram were recorded to evaluate left ventricular function.

Results

All patients presented in advanced stage with New York heart association class III (67.7%) and IV (32.3%). There was significant decline in left ventricular ejection fraction (with the mean value from 64.58 to 40.13%) and global longitudinal strain (- 15.57 ± 4.98to - 8.97) in the immediate postoperative period (~ 7 days). However, there was a rise in both left ventricular ejection fraction (mean 52.48%) and in global longitudinal strain (mean - 14.44 ± 3.67) at 3 months. Left ventricular and atrial size decreased significantly immediately after surgery, which further declined at 3 months. We also found that patients who attained a left ventricular ejection fraction of > 50% in postoperative period had better left ventricular ejection fraction and global longitudinal strain preoperatively. In addition, they had smaller cardiac size and milder pulmonary hypertension comparatively.

Conclusions

Mitral valve replacement in mitral regurgitation results in decline in left ventricular function immediately after surgery. In patients with chronic mitral regurgitation, left ventricular ejection fraction is fallacious and global longitudinal strain can be an important tool to assess left ventricular ejection fraction.

Left ventricular remodeling after mini-mitral repair-does the complexity of mitral disease matter?

OBJECTIVES

Degenerative mitral valve (MV) regurgitation (MR) is associated with left ventricular (LV) dilatation. Surgical treatment of MR has been shown to favorably affect LV remodeling. We prospectively compared the long-term echocardiographic outcomes of LV remodeling following mini-mitral repair for simple versus complex MV disease.

METHODS

We prospectively followed up 203 consecutive patients who underwent mini-MV repair for severe degenerative MR over a 9-year period. Simple disease (n = 122 patients: posterior leaflet prolapse) was compared to complex disease (n = 81 patients: anterior, bilateral or commissural prolapse). Baseline demographics were similar between simple and complex groups (age: 63 ± 13 years vs 60 ± 15 years; p = .2; sex: 71% male vs 72% male, p = 1; preoperative MR grade ≥ 3+: 100%; n = 122; vs 100%; n = 81; p = 1), respectively.

RESULTS

Preoperative left ventricular ejection fraction (LVEF) was significantly lower in the complex group as compared to the simple group (57.2% simple vs 56.0% complex; p = .04). Preoperative LV end-systolic diameter (LVESD: 35 mm simple vs 36 mm complex, p < .05) and LV end-diastolic diameter (LVEDD: 50 mm simple vs 51 mm complex; p < .05), as well as LV mass index (99.5 g/m² vs 102.4 g/m² ; p = .06) were larger in the complex group. Despite different baseline characteristics of LV function and geometry, both groups had similar remodeling of LV after MV repair.

CONCLUSIONS

Patients with complex MV disease are referred late for surgical repair, causing LV function and dimensions to never fully recover. This suggests that earlier referral (before LV changes and potentially before symptoms) may be the preferred approach in those with complex disease.

Beating-Heart Mitral Valve Repair Using a Novel ePTFE Cordal Implantation Device: A Prospective Trial

BACKGROUND

Conventional mitral valve (MV) operations allow direct anatomic assessment and repair on an arrested heart, but require cardiopulmonary bypass, aortic cross-clamping, sternotomy or thoracotomy, and cardioplegic cardiac arrest, and are associated with significant perioperative disability, and risks of morbidity and mortality.

OBJECTIVES

This study evaluated safety and performance of a transesophageal echocardiographic-guided device designed to implant artificial expanded polytetrafluoroethylene (ePTFE) cords on mitral leaflets in the beating heart.

METHODS

In a prospective multicenter study, 30 consecutive patients with severe degenerative mitral regurgitation (MR) were treated with a mitral valve repair system (MVRS) via small left thoracotomy. The primary (30-day) endpoint was successful implantation of cords with MR reduction to moderate or less.

RESULTS

The primary endpoint was met in 27 of 30 patients (90%). Three patients required conversion to open mitral surgery. There were no deaths, strokes, or permanent pacemaker implantations. At 1 month, MR was mild or less in 89% (24 of 27) and was moderate in 11% (3 of 27). At 6 months, MR was mild or less in 85 % (22 of 26), moderate in 8% (2 of 26), and severe in 8% (2 of 26). Favorable cardiac remodeling at 6 months included decreases in end-diastolic (161 ± 36 ml to 122 ± 30 ml; p < 0.001) and left atrial volumes (106 ± 36 ml to 69 ± 24 ml; p < 0.001). The anterior-posterior mitral annular dimension decreased from 34.7 ± 5.8 mm to 28.2 ± 5.1 mm; p < 0.001 as did the mitral annular area (10.0 ± 2.7 cm² vs. 6.9 ± 2.0 cm²; p < 0.0001).

CONCLUSIONS

MVRS ePTFE cordal implantation can reduce the invasiveness and morbidity of conventional MV surgery. The device's safety profile is promising and prospective trials comparing the outcomes of the MVRS to conventional MV repair surgery are warranted. (CE Mark Study for the Harpoon Medical Device [TRACER]; NCT02768870).

Incremental Value of Two Dimensional Speckle Tracking Echocardiography in the Functional Assessment and Characterization of Subclinical Left Ventricular Dysfunction

Subclinical left ventricular (LV) dysfunction refers to subtle abnormalities in LV function which typically precede a reduction in the left ventricular ejection fraction (LVEF). The assessment of myocardial function using LVEF, a radial metric of systolic function, is subject to load dependence, intra-observer and inter-observer variability. Reductions in LVEF typically manifest late in the disease process thus compromising the ability to intervene before irreversible impairment of systolic performance sets in. 2-Dimensional speckle tracking echocardiography (2D-STE), a novel strain imaging modality has shown promise as a sensitive indicator of myocardial contractility. It arms the clinician with a powerful and practical tool to rapidly quantify cardiac mechanics, circumventing several inherent limitations of conventional echocardiography. This article highlights the incremental utility of 2D-STE in the detection of subclinical LV dysfunction.

Strain balance of papillary muscles as a prerequisite for successful mitral valve repair in patients with mitral valve prolapse due to fibroelastic deficiency

AIMS

The aim of this study was to assess the papillary muscle strain as a contributor to recurrent mitral regurgitation (MR) after mitral valve repair for fibroelastic deficiency.

METHODS AND RESULTS

Sixty-four patients with isolated posterior mitral valve prolapse and severe MR referred for surgery were prospectively recruited between 2008 and 2012. Two- and three-dimensional echocardiography and speckle tracking were performed in all patients. The longitudinal strain of the anterolateral (AL) and posteromedial (PM) papillary muscles was individually calculated as well as the global longitudinal strain of both papillary muscles was measured before and after mitral repair and normalized to left ventricle end-diastolic volume. Eight patients (12.5%) had at least moderate MR 6 months after mitral repair. The longitudinal strain of the AL (preop -4.94 ± 2.2 vs. postop -3.28 ± 1.3, P < 0.001) and the PM papillary muscles (preop -12.64 ± 5.3 vs. postop -4.12 ± 6.77, P < 0.001) as well as the global strain of both papillary muscles (preop -7.59 ± 3.48 vs. postop -1.07 ± 6, P < 0.001) were all reduced after surgical repair. The longitudinal strain of the PM papillary muscle was the strongest predictor of recurrent MR (when less than or equal to -14.78). The global preoperative papillary muscle strain was also a determinant of recurrent MR when the global strain was greater than -9.05% (area under the curve: 0.895, sensitivity: 100%, and specificity: 76.8%).

CONCLUSIONS

Patients with isolated posterior mitral leaflet prolapse are less likely having any residual MR post repair when the global papillary muscle strain of both papillary muscles is close or equal to zero. Strain of the papillary muscles may be an important determinant in predicting residual MR in patients who undergo mitral valve repair.

Noninvasive clinical assessment of systolic torsional motions by two-dimensional speckle-tracking echocardiography in dogs with myxomatous mitral valve disease

BACKGROUND

Left ventricular torsional motion plays an important role for effective pump function. However, noninvasive clinical assessment of torsional deformations by two-dimensional speckle-tracking echocardiography (2D-STE) in dogs with myxomatous mitral valve disease (MMVD) has not been reported.

HYPOTHESIS

Left ventricular torsion is determined by the native orientation of the helical myocardial fibers, such that it might provide better assessment of myocardial function than conventional methods.

ANIMALS

Sixty-seven client-owned dogs with MMVD were classified into 3 classes based on the International Small Animal Cardiac Health Council classification and 16 weight- and age-matched healthy dogs.

METHODS

Dogs were examined for myocardial deformations by 2D-STE and were evaluated for peak systolic rotation and rotation rate at each basal and apical view. Dogs also were evaluated for peak systolic torsion and torsion rate.

RESULTS

Peak systolic torsion was higher in class II than in class I (P < .001) dogs. Peak systolic torsion was lower in class III than in class II (P = .001) dogs and controls (P = .003).

CONCLUSIONS AND CLINICAL IMPORTANCE

Torsional deformations assessed by 2D-STE differed among clinical classes of MMVD. Myocardial torsional deformations by 2D-STE may provide more detailed assessment of contractile function in dogs with MMVD.