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.

Geometric Changes in Mitral Valve Apparatus during Long-term Cardiac Resynchronization Therapy as Assessed with Cardiac CT.

Purpose To assess long-term geometric changes of the mitral valve apparatus using cardiac CT in individuals who underwent cardiac resynchronization therapy (CRT). Materials and Methods Participants from a randomized controlled trial with cardiac CT examinations before CRT implantation and at 6 months follow-up (Clinicaltrials.gov identifier NCT01323686) were invited to undergo an additional long-term follow-up cardiac CT examination. The geometry of the mitral valve apparatus, including mitral valve annulus area, A2 leaflet angle, tenting height, and interpapillary muscle distances, were assessed. Geometric changes at the long-term follow-up examination were reported as mean differences (95% CI), and the Pearson correlation test was used to assess correlation between statistically significant geometric changes and left ventricular (LV) volumes and function. Results Thirty participants (mean age, 68 years ± 9 [SD]; 25 male participants) underwent cardiac CT imaging after a median long-term follow-up of 9.0 years (IQR, 8.4-9.4). There were reductions in end-systolic A2 leaflet angle (-4° [95% CI: -7, -2]), end-systolic tenting height (-1 mm [95% CI: -2, -1]), and end-systolic and end-diastolic interpapillary muscle distances (-4 mm [95% CI: -6, -2]) compared with pre-CRT implantation values. The mitral valve annulus area remained unchanged. LV end-diastolic and end-systolic volumes decreased (-68 mL [95% CI: -99, -37] and -67 mL [95% CI: -96, -39], respectively), and LV ejection fraction increased (13% [95% CI: 7, 19]) at the long-term follow-up examination. Changes in interpapillary muscle distances showed moderate to strong correlations with LV volumes (r = 0.42-0.72; P < .05), while A2 leaflet angle and tenting height were not correlated to LV volumes or function. Conclusion Among the various geometric changes in the mitral valve apparatus after long-term CRT, the reduction in interpapillary muscle distances correlated with LV volumes while the reduced A2 leaflet angle and tenting height did not correlate with LV volumes. Keywords: Mitral Valve Apparatus, Cardiac Resynchronization Therapy, Cardiac CT Supplemental material is available for this article. © RSNA, 2024.

Echocardiographic quantification of mitral apparatus morphology and dynamics in patients with dilated cardiomyopathy.

Mitral regurgitation is among the most common valvular heart diseases. Mitral regurgitation in patients with dilated cardiomyopathy is a complex pathology involving annular dilatation, papillary muscle displacement, systolic leaflet tethering, and left ventricular remodeling. Quantification of mitral apparatus damage in these patients is essential for successful interventional and surgical therapy. Mitral regurgitation in the presence of dilated cardiomyopathy is classified as Carpentier type IIIB, with restricted leaflet mobility as a standard feature. Echocardiography allows accurate evaluation of the complex anatomy and function of the mitral apparatus. Updated guidelines recommend two-dimensional followed by systematic three-dimensional echocardiographic evaluation in patients with mitral regurgitation. New three-dimensional echocardiographic software packages provide many parameters that help identify the precise morphology and function of the various components of the mitral apparatus, helping to determine the etiology of mitral regurgitation and evaluate disease severity. This review provides the first point-by-point approach to the assessment of all old and new echocardiographic methods, from the simplest to the most complex, used to examine the components of the mitral valve apparatus in patients with dilated cardiomyopathy. Although these parameters are still under research, this information will be helpful for establishing therapeutic procedures in a disease with a poor prognosis.

Comparison of Nonclassic and Classic Phenotype of Hypertrophic Cardiomyopathy Focused on Prognostic Cardiac Magnetic Resonance Parameters: A Single-Center Observational Study.

Patients with nonclassic phenotypes (NCP)­more advanced stages of hypertrophic cardiomyopathy (HCM)­constitute an intriguing and heterogeneous group that is difficult to diagnose, risk-stratify, and treat, and often neglected in research projects. We aimed to compare cardiac magnetic resonance (CMR) parameters in NCP versus classic phenotypes (CP) of HCM with special emphasis given to the parameters of established and potential prognostic importance, including numerous variables not used in everyday clinical practice. The CMR studies of 88 patients performed from 2011 to 2019 were postprocessed according to the study protocol to obtain standard and non-standard parameters. In NCP, the late gadolinium enhancement extent expressed as percent of left ventricular mass (%LGE) and left ventricular mass index (LVMI) were higher, left atrium emptying fraction (LAEF) was lower, minimal left atrial volume (LAV min) was greater, and myocardial contraction fraction (MCF) and left ventricular global function index (LVGFI) were lower than in CP (p < 0.001 for all). In contrast, HCM risk score and left ventricular maximal thickness (LVMT) were similar in NCP and CP patients. No left ventricular outflow tract obstruction (LVOTO) was observed in the NCP group. Left ventricular outflow tract diameter (LVOT), aortic valve diameter (Ao), and LVOT/Ao ratio were significantly higher and anterior mitral leaflet (AML)/LVOT ratio was lower in the NCP compared to the CP group. In conclusion, significant differences in nonstandard CMR parameters were noted between the nonclassic and classic HCM phenotypes that may contribute to future studies on disease stages and risk stratification in HCM.

The current diagnosis and treatment of high-risk patients with chronic primary and secondary mitral valve regurgitation.

Mitral valve regurgitation (MR) is due primarily to either primary degeneration of the mitral valve with Barlow's or fibroelastic disease or is secondary to ischemic or nonischemic cardiomyopathies. Echocardiography is essential to assess MR etiology and severity, the remodeling of cardiac chambers and to characterize longitudinal chamber changes to determine optimal therapies. Surgery is recommended for severe primary MR if persistent symptoms are present or if left ventricle dysfunction is present with an EF <60% or a left ventricle end-systolic diameter ≥40 mm. For secondary MR, therapy of heart failure with vasodilators and diuretics improves forward cardiac output. Coronary artery bypass grafts (CABG) or percutaneous coronary intervention (PCI) should be considered for severe MR due to ischemia. This review summarizes the pathophysiology, the characteristics, the management and the different interventions for high risk patients with chronic primary and secondary MR.

Abnormal mitral valve apparatus in a case of hypertrophic obstructive cardiomyopathy: Intraoperative transesophageal echocardiography.

Hypertrophic obstructive cardiomyopathy is a relatively common disorder that signifies asymmetric hypertrophy of interventricular septum causing obstruction of the left ventricular outflow tract (LVOT). However, more recent studies have shown that during ventricular systole, flow against an abnormal mitral valve apparatus results in drag forces on the part of the leaflets. The mitral leaflet is pushed into the LVOT to obstruct it. We present a case where intraoperative transesophageal echocardiography played a crucial role in defining the etiology of LVOT obstruction that subsequently helped in deciding the surgical plan.

Cardiac 3D Printing and its Future Directions.

Three-dimensional (3D) printing is at the crossroads of printer and materials engineering, noninvasive diagnostic imaging, computer-aided design, and structural heart intervention. Cardiovascular applications of this technology development include the use of patient-specific 3D models for medical teaching, exploration of valve and vessel function, surgical and catheter-based procedural planning, and early work in designing and refining the latest innovations in percutaneous structural devices. In this review, we discuss the methods and materials being used for 3D printing today. We discuss the basic principles of clinical image segmentation, including coregistration of multiple imaging datasets to create an anatomic model of interest. With applications in congenital heart disease, coronary artery disease, and surgical and catheter-based structural disease, 3D printing is a new tool that is challenging how we image, plan, and carry out cardiovascular interventions.

Anatomy and Function of the Normal and Diseased Mitral Apparatus: Implications for Transcatheter Therapy.

Transcatheter mitral valve therapy requires an in-depth understanding of the mitral valve apparatus (annulus, leaflets, chordae tendinae, and papillary muscles) and the impact of various disease states. Adjacent structures (left atrium, left ventricular outflow tract, aortic valve, coronary sinus, and circumflex artery) must also be respected. This article reviews the anatomy and function of the normal and diseased mitral valve apparatus and the implications for catheter-based intervention.