Sudden death in young females with floppy mitral valve syndrome

Arrhythmogenic Mitral Valve Prolapse: Can We Risk Stratify and Prevent Sudden Cardiac Death?

Ventricular arrhythmias associated with mitral valve prolapse (MVP) and the capacity to cause sudden cardiac death (SCD), referred to as 'malignant MVP', are an increasingly recognised, albeit rare, phenomenon. SCD can occur without significant mitral regurgitation, implying an interaction between mechanical derangements affecting the mitral valve apparatus and left ventricle. Risk stratification of these arrhythmias is an important clinical and public health issue to provide precise and targeted management. Evaluation requires patient and family history, physical examination and electrophysiological and imaging-based modalities. We provide a review of arrhythmogenic MVP, exploring its epidemiology, demographics, clinical presentation, mechanisms linking MVP to SCD, markers of disease severity, testing modalities and management, and discuss the importance of risk stratification. Even with recently improved understanding, it remains challenging how best to weight the prognostic importance of clinical, imaging and electrophysiological data to determine a clear high-risk arrhythmogenic profile in which an ICD should be used for the primary prevention of SCD.

Morphologic comparison of patients with mitral valve prolapse who died suddenly with patients who died from severe valvular dysfunction or other conditions

Clinical and necropsy findings are described in 56 patients with mitral valve prolapse: 15 patients, aged 16 to 69 years (mean 39), died suddenly and mitral valve prolapse was the only cardiac condition found at necropsy (hereafter called isolated mitral valve prolapse); the remaining 41 patients had other conditions that were capable of being fatal. Of the latter 41 patients, 7, aged 17 to 59 years (mean 45), had associated congenital heart disease, and 34 patients, aged 17 to 70 years (mean 52), had no associated congenital cardiac abnormalities. Compared with the 34 patients without associated congenital heart disease and with nonmitral valve prolapse conditions capable in themselves of being fatal, the 15 patients who died suddenly with isolated mitral valve prolapse were younger (mean age 39 +/- 17 versus 52 +/- 15 years; p = 0.01), more often women (67% versus 26%; p = 0.008) and had a lower frequency of mitral regurgitation (7% versus 38%; p = 0.02). The 15 patients dying suddenly with isolated mitral valve prolapse also were less likely to have evidence of ruptured chordae tendineae (29% versus 67%; p = 0.04). The frequency of increased heart weight (67% versus 59%), a dilated mitral valve anulus (80% versus 81%), a dilated tricuspid valve anulus (17% versus 17%), an elongated anterior mitral leaflet (86% versus 54%), an elongated posterior mitral leaflet (79% versus 77%) and fibrous endocardial plaque under the posterior mitral leaflet (73% versus 63%) was similar between the two groups. The severity of the prolapse (mild 20% versus 11%; moderate 27% versus 58%; severe 53% versus 32%) also was similar between the two groups. Thus, persons with mitral valve prolapse dying suddenly without another recognized condition tend to be relatively young women without mitral regurgitation.

Mitral valve prolapse: cardiac arrest with long-term survival

Cardiac arrest has been reported in patients with mitral valve prolapse; however, clinical characteristics and survival information are limited since most of the cases reported include autopsy data. Nine patients (2 male, 7 female) with mitral valve prolapse were identified who had cardiac arrest; ventricular fibrillation was documented in 8 patients; resuscitation was unsuccessful in 2. Eight had a history of palpitations (months to 15 years duration) and ventricular arrhythmias, 3 had a history (5-15 years) of recurrent syncope, and 1 was totally asymptomatic. Cardiac catheterization-angiographic studies in 8 patients demonstrated normal coronary artery anatomy and mitral valve prolapse. All 9 patients had auscultatory and echocardiographic evidence of mitral valve prolapse. Seven survivors (6 still alive) were followed from 3 to 14 years after cardiac arrest. A subset of patients with mitral valve prolapse and cardiac arrest is described in whom past medical history is compatible with cardiac arrhythmias or syncope, and whose long-term prognosis appears better than patients with other causes of cardiac arrest.

Acute rupture of myxomatous mitral valve presenting as refractory cardiopulmonary arrest

A 59 year old white woman had an out of hospital sudden cardiac arrest. Resuscitation at the scene restored spontaneous pulse, blood pressure and respiration but cardiovascular collapse recurred within 30 minutes of hospital arrival. Medically refractory cardiogenic shock of unclear origin prompted the placement of an intraaortic balloon pump, and hemodynamic stabilization was achieved over several hours. Acute rupture of the chordae tendineae of myxomatous mitral valve was diagnosed as the cause of the cardiac arrest. Mitral valve replacement was performed and the patient made an uneventful recovery. This report describes the first known case of rupture of a myxomatous mitral valve presenting as sudden cardiac death. The differential diagnosis of sudden death in this disorder is reviewed, the role of mechanical circulatory assistance in refractory cardiac arrest is discussed and several interesting hemodynamic aspects of the case are considered.

Mitral valve prolapse: definition and implications in athletes

Mitral valve prolapse is probably the most common cardiac valve disorder, affecting approximately 5% of the population. Although it is genetically determined, its clinical manifestations do not usually become evident before adulthood. In the setting of a cardiology referral center, a mitral valve prolapse syndrome, consisting of nonspecific symptoms, repolarization changes on the electrocardiogram and arrhythmias, has been identified. However, doubt has recently been expressed about the existence of such a syndrome. The prognosis of mitral valve prolapse is generally favorable but infrequent complications do occur and include transient ischemic attacks, progression of mitral regurgitation with or without ruptured chordae tendineae, infective endocarditis and sudden death. The symptoms and the complications are not usually related to physical activity. A permissive attitude toward participation of patients with mitral valve prolapse in competitive athletics is probably warranted; however, it would appear reasonable to disqualify athletes with mitral valve prolapse in the following circumstances: history of syncope; disabling chest pain; complex ventricular arrhythmias, particularly if induced or worsened by exercise; significant mitral regurgitation; prolonged QT interval; Marfan's syndrome; and family history of sudden death.

Primary (spontaneous) chordal rupture: relation to myxomatous valve disease and mitral valve prolapse

The excised valves of 152 consecutive patients who underwent isolated primary mitral valve replacement between May 1979 and July 1983 were studied to determine the cause of primary (spontaneous) rupture of the chordae tendineae and estimate the prevalence of floppy mitral valve with underlying myxomatous disease. Of these 152 patients, 72 had nonrheumatic disease; 42 (28% of the total group) had a floppy valve, and 39 of these valves had microscopic changes of myxomatous disease. Primary chordal rupture had occurred in 31 patients, including 29 with myxomatous disease. Seven of these patients had prior documentation of mitral valve prolapse and an additional 20 patients had a long-standing murmur. Ischemic mitral regurgitation (22 patients) accounted for the majority of the remaining 30 patients with nonrheumatic disease. Therefore, approximately half of all isolated mitral valve replacements in this institution are now performed for nonrheumatic disease, the majority for a floppy valve in which myxomatous disease was the underlying abnormality. Primary chordal rupture almost invariably occurs as a complication of myxomatous disease, and mitral valve prolapse may be a common precursor.

Cardiac arrest under age 40: etiology and prognosis

Between January 1979 and December 1982, 84 patients between the ages of 1 and 39 years presented to the emergency department in a state of cardiac arrest. There were 58 male patients (69%) and 26 female patients (31%) in the group. Presenting rhythms were ventricular fibrillation (37%), asystole (37%), idioventricular rhythm (14%), heart block (4%), bradycardia (4%), ventricular tachycardia (3%), and electromechanical dissociation (3%). Thirty-two percent had bystander CPR. Of 21 patients initially resuscitated (25%), only four (5%) survived to discharge from the hospital. All survivors were neurologically intact. Seventy-five of the 80 patients who died (90%) underwent autopsy. Cause of death in the five remaining patients was inferred from clinical history. Etiologies of the cardiac arrests were the following: toxic exposure or ingestion (26%), atherosclerotic heart disease (23%), undetermined (11%), pulmonary embolism (6%), hemorrhage (6%), epilepsy (2%), cardiomyopathy (7%), myocarditis (2%), pneumonia (4%), and one case each of airway obstruction, asthma, peptic disease, and septic shock. Diverse etiologies should lead to a diagnostic search for reversible conditions in young patients. The prognosis for hospital discharge is poorer in the young population than is reported in our overall cardiac arrest population; however, numbers of neurologically intact survivors are similar in the young and the overall cardiac arrest population.

Mitral valve dysfunction in the Marfan syndrome. Clinical and echocardiographic study of prevalence and natural history

Although mitral regurgitation and fibromyxomatous thickening of the mitral leaflets have long been recognized as such, mitral valve prolapse has only recently been added as one of the pleiotropic features of the Marfan syndrome. The prevalence, age of onset, and natural history of mitral valve dysfunction in this condition are uncertain. Therefore, all patients in one clinic who met strict diagnostic criteria for the Marfan syndrome and who had clinical and echocardiographic examinations before age 22 years were reviewed. Of the 166 patients (84 males, aged 11.9 +/- 0.6 years [mean +/- SEM]; and 82 females, 11.0 +/- 0.6 years), 52 percent had auscultatory and 68 percent had echocardiographic evidence of mitral valve dysfunction, generally mitral valve prolapse. Prevalence did not differ between the sexes. Follow-up in 115 patients averaged five examinations over a mean of four years; 17 percent were followed for more than six years. Criteria for progression of mitral valve dysfunction were: (1) on auscultation, the appearance of new systolic clicks or apical systolic murmurs, a mitral regurgitant murmur increased by two grades, or appearance of congestive heart failure not due to aortic regurgitation; and (2) on echocardiography, the new appearance of mitral valve prolapse or abnormally increased left atrial dimension. Nearly half the patients met at least one criterion and one quarter had both auscultatory and echocardiographic evidence of progressive mitral valve dysfunction. Twice as many females demonstrated worse mitral valve function with time. Eight of the 166 patients either died as a result of mitral valve dysfunction or required mitral valve replacement. Severe mitral regurgitation developed in an additional 15 patients. Rupture of chordae tendineae was uncommon. Antibiotic prophylaxis was routine, and no cases of bacterial endocarditis of the mitral valve occurred. These results suggest that mitral valve dysfunction is extremely common in young patients with Marfan syndrome and usually presents as mitral valve prolapse. Serious mitral regurgitation develops in one of every eight patients by the third decade. Thus, the prevalence and natural history of mitral valve prolapse in the Marfan syndrome appear distinct from mitral valve prolapse associated with other conditions, including idiopathic or familial mitral valve prolapse.

The myxomatous mitral valve and sudden death

The clincopathologic features of 14 cases of sudden death attributable to dysrhythmias associated with the myxomatous mitral valve are described. The patients were 14-59 years old (mean 27 +/- 11 years). Eleven were female and three male. Of the seven ECGs available, none showed prolongation of the QT interval, but two showed repolarization abnormalities. The material was classified according to the degree of prolapse in the pathologic specimen. When obvious prolapse was found, the expected auscultatory findings had been documented. In three cases there was minimal prolapse, casting some doubt on the hypothesis that traction on the papillary muscles or diastolic dumping of the leaflets may be implicated in the pathogenesis of the dysrhythmias. In one of the cases with minimal prolapse there was a strong family history of sudden death. Endocardial friction lesions were present in 11 cases, including two of the three with minimal prolapse. In five cases there was a thrombotic lesion in the angle between the posterior leaflet and the left atrial wall containing fibrin and platelets. These abnormalities may be important in the pathogenesis of the ventricular dysrhythmias.