Arrhythmic risk profile in mitral valve prolapse: A systematic review and metanalysis of 1715 patients.

INTRODUCTION: Mitral valve prolapse (MVP) is a common clinical condition in the general population. A subgroup of patients with MVP may experience ventricular arrhythmias and sudden cardiac death ("arrhythmic mitral valve prolapse" [AMVP]) but how to stratify arrhythmic risk is still unclear. Our meta-analysis aims to identify predictive factors for arrhythmic risk in patients with MVP. METHODS: We systematically searched Medline, Cochrane, Journals@Ovid, Scopus electronic databases for studies published up to December 28, 2022 and comparing AMVP and nonarrhythmic mitral valve prolapse (NAMVP) for what concerns history, electrocardiographic, echocardiographic and cardiac magnetic resonance features. The effect size was estimated using a random-effect model as odds ratio (OR) and mean difference (MD). RESULTS: A total of 10 studies enrolling 1715 patients were included. Late gadolinium enhancement (LGE) (OR: 16.67; p = .005), T-wave inversion (TWI) (OR: 2.63; p < .0001), bileaflet MVP (OR: 1.92; p < .0001) and mitral anulus disjunction (MAD) (OR: 2.60; p < .0001) were more represented among patients with AMVP than in NAMVP. Patients with AMVP were shown to have longer anterior mitral leaflet (AML) (MD: 2.63 mm; p < .0001), posterior mitral leaflet (MD: 2.96 mm; p < .0001), thicker AML (MD: 0.49 mm; p < .0001), longer MAD length (MD: 1.24 mm; p < .0001) and higher amount of LGE (MD: 1.41%; p < .0001) than NAMVP. AMVP showed increased mechanical dispersion (MD: 8.04 ms; 95% confidence interval: 5.13-10.96; p < .0001) compared with NAMVP. CONCLUSIONS: Our meta-analysis proved that LGE, TWI, bileaflet MVP, and MAD are predictive factors for arrhythmic risk in MVP patients.

Five-year outcomes of mitral valve repair for leaflet prolapse at a medium-sized Norwegian university hospital.

Objective. To evaluate patient characteristics and 5-year outcomes after surgical mitral valve (MV) repair for leaflet prolapse at a medium-sized cardiothoracic center. Background. Contemporary reports on the outcome of MV repair at medium-sized cardiothoracic centers are sparse. Methods. Patients receiving open-heart surgery with MV repair due to primary mitral regurgitation caused by leaflet prolapse between 2015 and 2021, without active endocarditis, were included. Clinical data, complications, re-interventions, mortality, and echocardiographic data were retrospectively registered from electronical patient charts, both pre-operatively and from post-operative follow-ups. Results. One hundred and three patients were included, 83% male, with a mean age of 62 years. All-cause mortality was 9% during a median follow-up time of 4.9 years. Re-intervention rate on the MV was 4%. Post-operative complications before last available follow-up visit at median 3.0 years were infrequent, with new-onset atrial fibrillation/flutter in 16%, post-operative MV regurgitation grade II or above in 17% and post-operative tricuspid regurgitation grade II or above in 14%. Conclusions. These data demonstrate that surgical MV repair for leaflet prolapse at a medium-sized cardiothoracic center was associated with low re-intervention rate and few severe complications. The presented results are comparable to data from surgical high-volume centers, indicating that surgical MV repair can be safely performed at selected medium-sized cardiothoracic centers.

What Do We Know So Far About Ventricular Arrhythmias and Sudden Cardiac Death Prediction in the Mitral Valve Prolapse Population? Could Biomarkers Help Us Predict Their Occurrence?

PURPOSE OF THE REVIEW: To summarize currently available data on the topic of mitral valve prolapse (MVP) and its correlation to the occurrence of atrial and ventricular arrhythmias. To assess the prognostic value of several diagnostic methods such as transthoracic echocardiography, transesophageal echocardiography, cardiac magnetic resonance, cardiac computed tomography, electrocardiography, and electrophysiology concerning arrhythmic episodes. To explore intra and extracellular biochemistry of the cardiovascular system and its biomarkers as diagnostic tools to predict rhythm disturbances in the MVP population. RECENT FINDINGS: MVP is a common and mainly benign valvular disorder. It affects 2-3% of the general population. MVP is a heterogeneous and highly variable phenomenon with three structural phenotypes: myxomatous degeneration, fibroelastic deficiency, and forme fruste. Exercise intolerance, supraventricular tachycardia, and chest discomfort are the symptoms that are often paired with psychosomatic components. Though MVP is thought to be benign, the association between isolated MVP without mitral regurgitation (MR) or left ventricle dysfunction, with ventricular arrhythmia (VA) and sudden cardiac death (SCD) has been observed. The incidence of SCD in the MVP population is around 0.6% per year, which is 6 times higher than the occurrence of SCD in the general population. Often asymptomatic MVP population poses a challenge to screen for VA and prevent SCD. Therefore, it is crucial to carefully assess the risk of VA and SCD in patients with MVP with the use of various tools such as diagnostic imaging and biochemical and genetic screening.

Relationship between fragmented QRS complex and early left ventricular dysfunction after mitral valve repair.

BACKGROUND: Preoperative left ventricular (LV) ejection fraction (PreLVEF) and preoperative LV end-systolic diameter (PreESD) are known predictors for postoperative LV dysfunction after mitral valve repair (MVR). Fragmented QRS (fQRS) evaluated in 12-derivation electrocardiography has widely been accepted as a sign of myocardial fibrosis. In the present study, we aimed to evaluate the relationship between fQRS in preoperative 12­lead electrocardiography (ECG) and postoperative LV dysfunction that develop after MVR in patients with severe primary mitral regurgitation (MR) due to mitral valve prolapse (MVP). METHODS: From 2019 to 2022, 49 patients who had undergone successful MVR surgery for severeMR caused by MVP were enrolled in the study. The preoperative and postoperative echocardiographic data were collected retrospectively. We analyzed the demographic, echocardiographic, operative and postoperative parameters to assess the relationship between fQRS and early postoperative LV dysfunction, defined as an LVEF<60%. RESULTS: PreLVEF of all patients were ≥ %65. A total of 22 patients had fQRS (44.9%) and postoperative LV dysfunction was found to be 36.7%. A significantly higher rate of fQRS was observed in the group with postoperative LV dysfunction compared to the group without (12 (66.7%) vs 10 (32.3%), p: 0.036). In multivariate analysis for fQRS, PreESD, preoperative pulmonary artery systolic pressure (PrePASP), preoperative atrial fibrillation (PreAF), and male gender, only fQRS was found to be a significant predictor of postoperative LV dysfunction (p: 0.003, OR: 4.28, 95% CI (1.15-15.96). CONCLUSION: fQRS was found to be a predictor of postoperative LV dysfunction in the early period after MVR. fQRS may be a readily available and cost-effective test that can be used in clinical practice to predict postoperative LV dysfunction in patients undergoing MVR.

The Association Between Late Gadolinium Enhancement by Cardiac Magnetic Resonance and Ventricular Arrhythmia in Patients With Mitral Valve Prolapse: A Systematic Review and Meta-Analysis.

INTRODUCTION: Malignant ventricular arrhythmia (VA) and sudden cardiac death (SCD) have been reported in patients with mitral valve prolapse (MVP); however, effective risk stratification methods are still lacking. Myocardial fibrosis is thought to play an important role in the development of VA; however, observational studies have produced contradictory findings regarding the relationship between VA and late gadolinium enhancement (LGE) in MVP patients. The aim of this meta-analysis and systematic review of observational studies was to investigate the association between left ventricular LGE and VA in patients with MVP. METHODS: We searched the PubMed, Embase, and Web of Science databases from 1993 to 2023 to identify case-control, cross-sectional, and cohort studies that compared the incidence of VA in patients with MVP who had left ventricular LGE and those without left ventricular LGE. RESULTS: A total of 1464 subjects with MVP from 12 observational studies met the eligibility criteria. Among them, VA episodes were reported in 221 individuals (15.1%). Meta-analysis demonstrated that the presence of left ventricular LGE was significantly associated with an increased risk of VA (pooled risk ratio 2.96, 95% CI: 2.26-3.88, p for heterogeneity = 0.07, I2 = 40%). However, a meta-regression analysis of the prevalence of mitral regurgitation (MR) showed that the severity of MR did not significantly affect the association between the occurrence of LGE and VA (p = 0.079). CONCLUSION: The detection of LGE could be helpful for stratifying the risk of VA in patients with MVP.

Quantification of Mitral Regurgitation in Mitral Valve Prolapse by Three-Dimensional Vena Contracta Area: Derived Cutoff Values and Comparison With Two-Dimensional Multiparametric Approach.

BACKGROUND: Echocardiographic grading of mitral regurgitation (MR) in mitral valve prolapse (MVP) is challenging. Three-dimensional (3D) vena contracta area (VCA) has been proposed as a valuable method. However, data defining the cutoff values of severity and validation in the subset of patients with MVP are scarce. The aim of this study was to validate the 3D VCA by 3D color-Doppler transesophageal echocardiography (TEE) in patients with MVP and to define the cutoff values of severity grading. The secondary aim was to compare 3D VCA to the effective regurgitant orifice area estimation by proximal isovelocity surface area (EROA-PISA) method. METHODS: A total of 1,138 patients with at least moderate MR who underwent TEE were included. Three-dimensional VCA was measured, and the cutoff value and area under the curve (AUC) for the prediction of severe MR were estimated by receiver operating characteristic curve using a guideline-suggested multiparametric approach as the reference standard. In a subgroup of patients, 3D regurgitant volume (RV) and 3D fraction were calculated from mitral and left ventricular outflow tract stroke volumes to further validate 3D VCA against a 3D volumetric reference standard. RESULTS: The optimal 3D VCA cutoff value for predicting severe MR was 0.45 cm2 (specificity, 0.87; sensitivity, 0.90) with an AUC of 0.95 using a multiparametric approach as reference. Three-dimensional VCA had a good linear correlation with EROA-PISA (r = 0.62, P < .05) with larger values compared to EROA-PISA (0.63 cm2 vs 0.44 cm2, P < .05). A cutoff of 0.50 cm2 (AUC of 0.84; sensitivity, 0.78; specificity, 0.78) predicts an EROA-PISA of 0.40 cm2. Three-dimensional VCA had a good linear correlation with 3D RV (r = 0.56, P < .01), with an AUC of 0.86 to predict a 3D fraction >50%. CONCLUSIONS: The present study suggests 0.45 cm2 as the best cutoff value of 3D VCA to define severe MR in patients with MVP, showing an optimal agreement with the reference standard multiparametric approach and 3D RV.

Determinants of Ventricular Arrhythmias in Mitral Valve Prolapse.

BACKGROUND: Mitral valve prolapse (MVP) may be associated with ventricular arrhythmias (VA) even in the absence of significant valvular regurgitation. Curling, mitral annulus disjunction (MAD) and myocardial fibrosis (late gadolinium enhancement [LGE]) may account for arrhythmogenesis. OBJECTIVES: This study investigated the determinants of VA in patients with MVP without significant regurgitation. METHODS: This study included 108 patients with MVP (66 female; median age: 48 years) without valve regurgitation. All patients underwent 12-lead electrocardiography, 12-lead 24-hour electrocardiographic Holter monitoring, exercise stress test, and cardiac magnetic resonance. Patients were divided into 2 groups (arrhythmic and no-arrhythmic MVP), according to the presence of VA with a right bundle branch block pattern. RESULTS: The 62 patients (57%) with arrhythmic MVP showed: 1) higher MAD (median length: 6.0 vs 3.2 mm; P = 0.017); 2) higher prevalence of curling (79% vs 52%; P = 0.012); and 3) higher prevalence of left ventricular LGE (79% vs 52%; P = 0.012). Mediation analysis showed that curling had both a direct (P = 0.03) and indirect effect mediated by LGE (P = 0.04) on VA, whereas the association between MAD and VA was completely mediated by LGE. Patients with severe VA showed more pronounced morphofunctional alterations, in terms of MAD (7.0 vs 4.6 mm; P = 0.004) and presence and severity of curling (respectively, 91% vs 64%; P = 0.010; and 4 vs 3 mm; P = 0.004), compared to those without severe VA. CONCLUSIONS: In patients with MVP the occurrence of VA with right bundle branch block morphology is the expression of more severe morphologic, mechanical, and tissue alterations. Curling has both a direct and an indirect effect on VA.

Non-resectional cordal repair for Barlow mitral valve disease.

BACKGROUND: The redundant leaflet tissue and annular pathology of Barlow disease can make surgical repair challenging. We examined perioperative and late outcomes of a large cohort of patients with Barlow disease undergoing surgical repair. METHODS: Patients included in this analysis underwent mitral valve repair from 01/2004-11/2021 by a single surgeon. RESULTS: Of 2798 patients undergoing mitral valve operations, 46% (N.=1292) had degenerative pathology and 7% (N.=184) had Barlow disease. Of the 179 Barlow patients, median age at surgery was 62 (51-70) years; 64% were male (115/179). Rates of non-resectional cordal repair and resectional repair were 86% (154/179) and 14% (25/179). Among patients undergoing non-resectional repair, the median number of cordal pairs inserted on the anterior and posterior leaflets was 2 (2-3) and 4 (3-4). Incidence of return to bypass for systolic anterior motion of the mitral valve, perioperative death, stroke, and renal failure was 2% (4/179), 1% (2/179), 0% (0/179), and 0% (0/179). Rates of clinical and echocardiographic follow-up were 93% (165/177) and 89% (157/177). Median time to latest postoperative clinical and echocardiographic follow-up was 2.4 (0.8-6.1) and 2.1 (0.6-4.7) years. Mitral regurgitation grade at latest follow-up or time of repair failure was none/trace, mild, mild to moderate, and severe in 63% (98/157), 26% (41/157), 8% (12/157), and 4% (6/157); five of six patients with severe MR underwent reoperation. Since 2011 97% (139/144) of patients underwent cordal repair without resection. CONCLUSIONS: Non-resectional artificial cordal repair is safe and feasible in almost all patients with Barlow valves and is associated with excellent mid-term results.

Primary Atriopathy in Mitral Valve Prolapse: Echocardiographic Evidence and Clinical Implications.

BACKGROUND: Prominent multi-scallop systolic leaflet displacement toward the left atrium (atrialization) is typically observed in bileaflet mitral valve prolapse (MVP) with mitral annular disjunction. We hypothesized that mitral leaflet atrialization is associated with an underlying left atrial (LA) myopathy characterized by progressive structural and functional abnormalities, irrespective of mitral regurgitation (MR) severity. METHODS: We identified 334 consecutive patients with MVP, no prior atrial fibrillation, and comprehensive clinical and echocardiographic data. LA function was assessed by LA reservoir strain, LA function index, and LA emptying fraction. We also classified the stage of LA remodeling based on LA enlargement and LA reservoir strain (stage 1: no remodeling; stage 2: mild remodeling; stage 3: moderate remodeling; and stage 4: severe remodeling). The primary end point was the composite risk of sudden arrhythmic death, heart failure hospitalization, or the new onset of atrial fibrillation. RESULTS: Bileaflet MVP with no or mild MR had a lower LA reservoir strain (P=0.04) and LA function index (P<0.001) compared with other MVP subtypes. In multivariable linear regression adjusted for cardiovascular risk factors and MR ≥moderate, bileaflet MVP remained significantly associated with lower LA function parameters (all P<0.05). There was a significant increase in the risk of events as the LA reservoir strain and LA remodeling stage increased (P<0.001). In multivariable analysis, stage 4 of LA remodeling remained significantly associated with a higher risk of events compared with stage 1 (hazard ratio, 6.09 [95% CI, 1.69-21.9]; P=0.006). CONCLUSIONS: In a large MVP registry, bileaflet involvement is associated with reduced LA function regardless of MR severity, suggesting a primary atriopathy in this MVP subtype. Abnormal LA function, particularly when assessed through a multiparametric approach, is linked to a higher risk of cardiovascular events and may improve risk stratification in MVP, even in those without significant MR.

The relationship between mitral valve prolapse and thoracic skeletal abnormalities in clinical practice: a systematic review.

BACKGROUND: Literature data suggest high inter-study variability in mitral valve prolapse (MVP) prevalence among individuals with thoracic skeletal abnormalities (TSA). This systematic review aimed at estimating the overall prevalence of MVP in individuals with the most common TSA, including not only the oldest studies (before the year 2000) but also the most recent ones (after the year 2000). METHODS: PubMed and EMBASE databases were systematically reviewed in November 2023. Studies assessing the relationship between MVP and TSA and estimating the MVP prevalence in pectus excavatum (PE), pectus carinatum (PC), scoliosis, straight back syndrome (SBS) and Marfan syndrome (MS) were included. There was no limitation on time periods. RESULTS: Twenty-five studies with a total of 2800 patients (27.9 ±â€Š13.9 years, 48.2% females) were analyzed. The highest prevalence of MVP was observed among MS patients (47.3%), while the lowest was detected in PC individuals (23%). Prevalence of MVP was similar among PE (30.8%), scoliosis (26.3%) and SBS (25.5%) patients. When dividing the studies on the basis of temporal period, the average MVP prevalence was approximately two-fold higher in all studies conducted before the year 2000 in comparison with the most recent ones, regardless of TSA type. This discrepancy might be primarily ascribed to relevant differences in the echocardiographic criteria employed for MVP diagnosis before (less specific) and after (more specific) the year 2000, respectively. CONCLUSIONS: The estimated MVP prevalence in TSA individuals is significantly higher than that observed in the general population. Individuals with TSA should be screened for MVP presence on transthoracic echocardiography.

Relação entre reduçäo volumétrica do ventrículo esquerdo e incremento do prolapso da valva mitral: um estudo experimental em cäes / Experimental Study on the Relationship Between Reduction of Left Ventricular Volume and Increment of Mitral Valve Prolapse

PURPOSE--To verify whether accentuated reductions of left ventricular volume lead to mitral valve prolapse. METHODS--Seven mongrel dogs were bled through the internal jugular vein, the systolic systemic pressure being kept between 100 and 140 mmHg by means of continuous infusion of dopamine; the inferior vena cava vein, in tree other dogs, was partially obstructed for 4 to 6 seconds; epicardial echocardiography was carried out in all cases. RESULTS--Reductions of volemia were about 50 per cent of the estimated total blood volume. Systolic internal diameter of left ventricle decreased about 25 per cent and systolic ostial diameter, about 12.5 per cent . Three out of seven died suddenly from arrhythmia before one has reached a significant decrease in total blood volume; one showed momentary mitral valve prolapse, during a period of hypotension; however, this prolapse disappeared completely when systemic blood pressure was restored by increasing the dopamine dosage; one dog had slight systolic displacement of the anterior cusp toward left atrium (0.5mm) and the last two showed no change; one out of 3 dogs submitted to partial constriction of inferior vena cava had systolic displacement of anterior cusp of 1mm; in one case there was an equivalent degree of displacement of the anterior cusp toward the left ventricle and in the last one no change was detected. In all dogs there was a change in the dynamics of mitral valve closure: with accentuated reduction of left ventricular volume the posterior cusp became less mobile, the anterior cusp being the principal responsible for the systolic ostial occlusion. CONCLUSION--Accentuated reduction of dog's left ventricular volume does not, necessarily, cause mitral valve prolapse but only slight displacement of the anterior cusp toward the left atrium in some animals or no displacement at all

Objetivo - Verificar se diminuições acentuadas do volume ventricular esquerdo provocam o aparecimento de abaulamento sistólicos da valva mitral. Métodos - Sete cães foram submetidos a lenta sangria pela veia jugular interna (20 a 30min), mantendose os níveis sistólicos entre 100 e 140mmHg através da infusão contínua de dopamina; 3 cães foram submetidos a veno-constricções parciais e momentâneas (5-6s) da veia cava inferior; foi feita exploração ecocardiográfica epicárdica com transdutor de 5mHz em todos os casos. Resultados - Provocou-se redução da volemia estimada dos animais de até 50%, ocorrendo uma diminuição média do diâmetro ostial sistólico de 12,5% e redução média do diâmetro sistólico esquerdo de 25%. Tres dos 7 cães submetidos a sangria apresentaram arritmia grave e morreram antes de se conseguir uma diminuição apreciável do volume ventricular esquerdo; 1 exibiu momentâneo abaulamento sistólico mitral durante período de hipotensão que desapareceu com a elevação dos niíveis pressóricos por aumento da dose de dopamina e a despeito de se continuar a redução do volume ventricular pelo sangramento; 1 mostrou discreto deslocamento da cúspide anterior (0,5mm); os 2 últimos deste grupo não exibiram qualquer movimento da valva mitral em direção ao átrio esquerdo; dos 3 animais em constricção parcial da veia cava inferior, detectamos, em 1 deles, abaulamento sistólico da cúspide anterior de 1mm; em outro, a cúspide anterior exibiu um deslocamento de 1mm em direção ao ventrículo esquerdo, nada sendo observado no último animal. Em todos os 7 cães notou-se mudança da dinâmica do fechamento da valva mitral: com redução volumétrica do ventrículo esquerdo, a cúspide posterior passou a se mostrar menos móvel, cabendo à anterior o principal papel na oclusão do óstio atrioventricular. Conclusão - Reduções acentuadas do volume ventricular esquerdo produzidas por sangramento e por veno-constricção parcial da veia cava inferior não levam, necessariamente, a abaulamentos da valva mitral. Nossos achados contrapõem-se à admitida relação en tre incremento do prolapso da valva mitral e manobras clínicas que provocam redução do volume ventricular esquerdo

Prolapso da valva mitral e elasticidade cuspidiana / Mitral valve prolapse and cusp elasticity

PURPOSE--To verify if systolic bulging of floppy mitral cusps can to elastic behavior of their myxomatous collagen tissue. METHODS--Five hearts with floppy mitral valves obtained from autopsies were distended with air (20 to 250 mmHg) through a catheter connected to the left ventricle. It was observed if some area of the atrial surface of the coapted cusps showed variable bulging according to the variation of air injection pressures. Molding of those surfaces (gypsum) allowed the same kind of analysis by other four researches. It was analyzed the cut surfaces of these radially sectioned molds. Lately, isolated tendinae chords were submitted to repeated tractions and observed if they exhibited elastic behavior. Histological study defined the presence of collagen myxomatous degeneration and quantified the amount of elastic tissue. RESULTS--In no case it was detected elastic bulding of mitral cusps. Cut surfaces of the molds confirmed that no increment of the prominent areas occurred, even in those regions with extensive, histologically confirmed, myxomatous substitution of the native collagen tissue. CONCLUSION--Increment of the degree of mitral bulging occurring during ventricular systole can not be ascertained to cusp elasticity but probably to papilar muscle traction

Aspectos clínicos e eletrocardiográficos do prolapso da valva mitral / Clinical and electrocardiographic aspects of mitral valve prolapse

Foram analisados, retrospectivamente, a incidência quanto a sexo e idade, sintomatologia, alteraçöes do segmento ST e da onda T e dos intervalos QT e PR do eletrocardiograma, bem como distúrbio do ritmo cardíaco, em dois grupos de pacientes ambulatoriais: Grupo I (n = 63), com diagnóstico ecocardiográfico de prolapso da valva mitral (PVM) e Grupo II (n = 63), com ecocardiograma normal. Houve predomínio do sexo feminino em ambos os grupos, na proporçäo de 2,5:1 e 1,5:1, respectivamente. As idades variaram entre 15 e 69 anos, com mdia de 29,3 ñ 10,8 anos, no grupo I e entre 9 e 58 anos, com média de 26,5 ñ 10,1 anos, no grupo II. Palpitaçöes, dor precordial, em geral atípica e dispnéia, foram os sintomas mais freqüentes, ocorrendo em 52 casos (82,5%) do grupo I e em 45 (71,5%) do grupo II. As alteraçöes do segmento ST e da onda T ocorreram em apenas dois casos (4%) do grupo I e em oito casos (13%) do grupo II (p > 0,05). O intervalo PR se mostrou igual ou inferior a 0,20 s em todos os casos de ambos os grupos e o QTc estava prolongado em apenas dois casos (4%) do grupo I e em um (1,5%) do grupo II. As taquiarritmias, quando analisadas globalmente, pelo eletrocardiograma convencional, ocorreram em 17 casos (31,5%) do grupo I e em dez casos (16,5%) do grupo II. As extra-sístoles ventriculares ocorreram em 12 casos (22%) do grupo I e em oito casos (13%) do grupo II. Já a taquicardia paroxística supraventricular foi registrada em cinco pacientes (9%) do grupo I e em nenhum caso do grupo II...

Funçäo ventricular no prolapso de valva mitral: efeitos do bloqueio beta-adrenérgico com e sem atividade simpatomimética intrínseca / Ventricular function in mitral valve prolapse: effects of beta adrenergic blockers with and without intrisic sympathomimetic activity

Admite-se, de acordo com a teoria cardiomiopática da etiopatogenia do prolapso valvar mitral, que pode existir grau discreto de comprometimento miocárdico näo evidenciável em condiçäo basal, mas passível de ser desmascarado sob efeito de fatores depressores associados. Como os bloqueadores beta-adrenérgicos constituem opçäo primeira no controle sintomático desses pacientes, testou-se a hipótese de que o seu efeito depressor pudesse ser evidenciado em pacientes com prolapso valvar mitral. Os resultados deste estudo, utilizando avaliaçäo da funçäo ventricular por métodos ecocardiográfico e angiocardiográfico nuclear, näo säo indicativos da presença de processo cardiomiopático em tais pacientes. Entretanto, foi possível verificar, ainda que dentro dos limites da normalidade para desempenho ventricular, reduçäo da fraçäo de ejeçäo, da freqüência cardíaca e da velocidade máxima de esvaziamento ventricular, sob açäo de bloqueador sem atividade simpatomimética intrínseca (propranolol), mas näo de bloqueador provido de atividade simpatomimética intrínseca (pindolol)

Prolapso sintomático da válvula mitral: disfunçäo ventricular esquerda e efeito benéfico do digitálico / Symptomatic mitral valve prolapse: left ventricular dysfunction and beneficial effect of digitalis

Objetivo - Estudar a funçäo ventricular esquerda pela ecocardiografia modo M de pacientes sintomáticos com prolapso da válvula mitral (PVM) primário, sem insuficiência mitral significante, durante a prova da fenilefrina, antes e após a digitalizaçäo. Métodos - Foram estudados 31 pacientes com PVM e 10 indivíduos normais como grupo de controle. Pela ecocardiografia modo M foram medidos: percentagem do encurtamento sistólico (DD), fraçäo de ejeçäo (FE) e velocidade média de encurtamento circunferencial e velocidade média de encurtamento circunferencial das fibras (Vcf). Os traçados ecocardiográficos foram realizados em repouso e durante a infusäo lenta de fenilefrina (40-60 ug/min) a fim de permitir aumentos da pressäo arterial sistólica de 20 a 30 mmHg. Resultados - Em repouso, o tamanho e a funçäo cardíaca foram normais em ambos os grupos, porém durante a infusäo de fenilefrina, 27 pacientes apresentaram diminuiçöes na DD (de 37.7 ñ 4,6 para 31, 0 ñ 4,0, p < 0,001, na FE (de 0,76 ñ 0,05 para 0,66 ñ 0,6, p 0,001 e no Vef (de 1,05 ñ 0,77 para 0,76 ñ 0,13 cir/s, p < 0,001). Desse grupo, 20 pacientes após a digitalizaçäo, durante o teste de fenilefrina, näo apresentaram alteraçöes na DD (de 38,3 ñ 5,0 para 39,2 ñ 3,8 NS); FE (de 0,77 ñ 0,06 para 0,77 ñ 0,004, NS) e no Vef (de 1,05 ñ 0,19 para 0,94 ñ 0,13, cir/s, NS). Esses pacientes, digitalizados, durante o teste ergométrico submáximo apresentaram aumentos significantes do trabalho total (de 617 ñ 248 para 982 ñ 244 watts, p < 0,001) e da eficiência cardíaca (de 25,0 ñ 11,5 para 37,2 ñ 10,4, p 0,001). Por outro lado, a infusäo de fenilefrina no grupo controle, näo provocou alteraçöes na DD, FE e VcF. Conclusäo - Pacientes sintomáticos com PVM primário, sem insuficiência mitral significativa, apresentam durante a prova de fenilefrina uma total recuperaçäo da disfunçäo ventricular esquerda, quando digitados, com melhora significativa do trabalho total e da eficiência cardíaca no teste de esforço

Purpose - To study the left ventricular function by M-mode echocardiography in symptomatic patients with primary mitral valve prolapse (MVP), without significant mitral regurgitation, during the phenylephrine test, before and after digitalization. Methods - Thirty one patients with MVP and 10 normal subjects as a control group were studied by M mode echocardiography: Percentage of systolic shortening ( DD), ejection fraction (EF) and mean velocity of circunferential fibers shortening (Vcf) were measured. The echocardiographic recordings were obtained at rest and during the continuous infusion of phenylephrine (40-60 ug/min) in order to allow an increase of 20-30 mmHg in systalic pressure. Results - At rest, cardiac size and function were normal in both groups. During phenylephrine infusion in 27 patients a decrease in DD (from 37.7 ±4.6 to 31.0 ± 4.0, p<0.001); in EF (from 0.76 ± 0.05 to 0.66 ± 0.6, p<0.001); in Vcf (from 1.05 ± 0.77 to 0.76 ± 0.13, p<0.001) were observed. From this group 20 patients received digoxin. After the digitalization the phenylephrine test did not cause changes in DD (from 38.3 ± 5.0 to 39.2 ± 3.8, NS); in EF (from 0.77 ± 0.06 to 0.77 ± 0.04, NS); in Vcf (from 1.05 ± 0.19 to 0.94 ± 0.13,NS). These patients during the submaximal exercise test, showed significant increases at the total work load (from 617 ± 248 to 982 ± 244 watts, p<0.001) and cardic efficiency (from 25.0 ± 11.5 to 37.2 ± 10.4, p<0.001). On the other hand the phenylephrine infusion in the control group did not result in changes in DD, EF and Vcf. Conclusion - Symptomatic patients with primary MVP showed total recovering of left ventricular dysfunction with digitalization during the phenylephrine test, with improvement of cardiac efficiency

Comparação ecodopplercardiográfica da dinâmica valvar entre atletas ciclistas, corredores e futebolistas e indivíduos sedentários / Comparative Doppler Echocardiographic Assesement of Valvar Function in Cyclists, Runners and Soccer Players Athletes, and Sedentary Subjects

PURPOSE--To compare the patterns of valvar dynamics expressed by the mitral prolapse and regurgitation across the valves, between competitive athletes players of distinctive sport modalities, and between these and sedentary control subjects. METHODS--Pulsed and continuous wave non-colour Doppler echocardiographic evaluation of mitral valvular movements and flow patterns across the different valves was comparatively performed in 10 cyclists, 10 runners, 19 football players, and in 17 sedentary nonathletes controls, all males with ages ranging between 16 and 28 years old (p > 0.05). Valvar dynamics was evaluated from the apical two and four-chamber and parasternal short-axis and long-axis views. The proportions of valvar functional patterns in each group were compared using the chi-square test. RESULTS--Similar (p > 0.05) and high frequency of mitral prolapse were detected in the cyclists (30 per cent ), runners (50 per cent ), football players (32 per cent ), and controls (47 per cent ). Mitral, tricuspid and pulmonary regurgitations were very frequent and their proportions similar (p > 0.05) in the cyclists (40 per cent , 80 per cent and 40 per cent , respectively), runners (50 per cent , 70 per cent and 60 per cent ), football players (37 per cent , 58 per cent and 58 per cent ), and controls (41 per cent , 35 per cent and 35 per cent ). No significant difference (p > 0.05) was observed between cyclists (20 per cent ), runners (20 per cent ), football players (16 per cent ), and controls (35 per cent ) for the frequency of mitral prolapse plus regurgitation. Aortic regurgitation was not observed in any athlete or control subject. CONCLUSION--Neither the practice, nor the sport modalities studied appears to influence the prevalence of mitral prolapse and mitral, tricuspid and pulmonary valvar regurgitation. In all likelihood, these manifestations represent physiological variants of valvar dynamic which can be better detected by means of Doppler echocardiography

Objetivo - Comparar os padrões de dinâmica valvar traduzidos pelo prolapso da valva mitral (PVM) e refluxos valvares entre atletas competidores de modalidades esportivas distintas e, entre estes, e indivíduos sedentários. Métodos - A dinâmica valvar foi avaliada pela ecocardiografia com Doppler pulsado e contínuo não colorido, por meio dos cortes apicais de 2 e 4 câmaras e paraesternais longitudinal e transversal, em 10 ciclistas, 10 corredores, 19 futebolistas e em 17 controles sedentários, todos do sexo masculino, com idades entre 16 e 28 anos (p>0,05). As proporções dos padrões funcionais valvares em cada grupo foram comparadas pelo teste do qui-quadrado. Resultados - A freqüência de PVM foi elevada e semelhante (p>0,05) nos ciclistas (30%), corredores (50%), futebolistas (32%) e controles (47%). Regurgitação através das valvas mitral, tricúspide e pulmonar foi achado freqüente e suas proporções não diferiram (p>0,05) entre ciclistas (40%, 80% e 40%, respectivamente), corredores (50%, 70% e 60%), futebolistas (37%, 58% e 58%) e indivíduos controles (41%, 35% e 35%). A freqüência de PVM associado com regurgitação através desta valva, também mostrou-se semelhante (p>0,05) nos ciclistas (20%), corredores (20%), futebolistas (16%) e indivíduos sedentários (35%). Regurgitação aórtica não foi observada em quaisquer dos grupos. Conclusão - Nem a prática regular e nem a modalidade do exercicio físico mantido por ciclistas, corredores e futebolistas, parecem modificar a dinâmica valvar. As elevadas e semelhantes freqüências de PVM e de refluxos valvares encontradas nos diferentes grupos, sugerem que estas manifestações funcionais sejam variantes fisiológicas da dinâmica valvar, melhor identificadas pela ecodopplercardiografia

Orientaçäo esquerda da AQRS e prolapso da valva mitral na infância: correlaçäo eletro-ecocardiográfica em 28 casos / Lftaxis derivation of QRS and prolapse of mitral valve in infnacy: echo-electrocardiographic correlation in 28 cases

A partir do registro de prolapso da valva mitral em 28 crianças, pelo ecocardiograma bidimensional, os autores analisaram o ECG obtido. Além de dados conhecidos, verificaram desvio do AQRS para a esquerda (+30- a - 15- no plano frontal), como achado mais significativo, presente na grande maioria do tipo considerado "primário" (65,2%). Baseados na caracterizaçäo dos bloqueios divisionais do ramos direito do feixe de His, os autores discutem uma possivel explicaçäo para o fato

Prevalência de prolapso valvar tricúspide e aórtico em portadores de prolapso valvar mitral / Prevalence of tricuspid and aortic valve prolapse in patients with mitral valve prolapse

Foram estudados, através da ecocardiografia bidimensional, 30 pacientes portadores de prolapso da valva mitral, sendo 15 do sexo feminino e 15 masculino, com idade média de 33,3 anos, com o objetivo de observar a prevalência de concomitante prolapso valvar tricúspide e aórtico. O prolapso da valva tricúspide foi obsrvado em 43,3% dos pacientes (13/30 anos, sendo que o folheto anterior e septal estava acometido em 92,3% e o posterior em 15,3% dos casos. A prevalência de prolapso da valva aórtica foi de 10% dos casos (3/30), estando ambos os folhetos avaliados - coronariano direito e näo coronariano - acometidos. Todos os pacientes com prolapso valvar aórtico apresentavam acometimento dos dois folhetos mitrais e de, no mínimo, dois folhetos tricuspídeos. Conclui-se que é comum o acometimento simultâneo das valvas tricúspide e aórtica em pacientes portadores de prolapso da valva mitral