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R Kramer-Fox

Publications and source records attributed to R Kramer-Fox.

32 records · Page 2Linked to original sources
PubMed1987

Contrasting patterns of autonomic dysfunction in patients with mitral valve prolapse and panic attacks.

Both mitral valve prolapse (MVP) and panic attacks have been reported to be associated with autonomic dysfunction, but previous studies have been limited by the lack of clear separation between patients with MVP and those with panic attacks and the use of noncomparable control subjects. Accordingly, heart rate and blood pressure responses to deep breathing, five minutes' quiet standing, and the Valsalva maneuver were studied in age- and cardiac symptom-matched groups of 33 control subjects, 66 patients with MVP, 20 patients with panic attacks, and 17 patients with both MVP and panic attacks. Compared with control subjects, patients with MVP exhibited more syncope (13 of 66, or 20 percent, versus none of 33, or 0 percent; p less than 0.01), more orthostatic hypotension during quiet standing (11 of 66, or 17 percent, versus one of 33, or 3 percent; p less than 0.01), loss of the normal decrease with age in vagally-mediated heart rate variability during deep breathing (r = 0.13, p = NS versus r = -0.44, p = 0.01), and lower 24-hour epinephrine excretion (6.1 +/- 0.7 versus 11.0 +/- 2.7 micrograms; p less than 0.01). In contrast, patients with panic attacks had greater increases than control subjects or patients with MVP without panic attacks in heart rate, mean blood pressure, and the product of heart rate and mean blood pressure during each minute of quiet standing and during the early strain phase of the Valsalva maneuver. These findings indicate that autonomic dysfunction occurs both in patients with MVP and in those with panic attacks in comparison with symptomatic control subjects, but that the patterns of abnormality differ. Patients with MVP exhibit decreased effectiveness of responses to orthostatic stress, reduced epinephrine excretion, and abnormal vagal tone, whereas patients with panic attacks have heightened cardiovascular responses to postural and positive intrathoracic pressure stresses.

Adult↗
PubMed1986

Complications of mitral valve prolapse. Disproportionate occurrence in men and older patients.

To determine factors influencing the strength of association between mitral valve prolapse and mitral regurgitation, ruptured chordae tendineae, and infective endocarditis, the prevalence of mitral prolapse in patients with disease was compared with both clinical and population control groups. The prevalence of mitral valve prolapse was 4 percent among population and clinical control groups (eight of 196 and 84 of 2,146, respectively) and was significantly higher (p less than 0.001) in patients with endocarditis (11 of 67, 16 percent), mitral regurgitation (17 of 31, 55 percent, and ruptured chordae (27 of 43, 63 percent). Odds ratios for complications in persons with mitral valve prolapse ranged from 4.6 for endocarditis to 41.4 for ruptured chordae in overall analyses, and from 6.8 for endocarditis to 53.0 for ruptured chordae based on age- and sex-matched case-control triplets (p less than 0.001 for each). All complications occurred disproportionately in men with mitral valve prolapse, in whom odds ratios ranged from 2.5 to 7.4 compared with an additional control group of unselected subjects with mitral valve prolapse. Compared with this control group, patients with mitral valve prolapse and endocarditis were slightly more likely to have a previously known heart murmur (odds ratio 3.2, difference not significant) but significantly more likely to have murmurs at the time of evaluation (odds ratio 8.5, p less than 0.01). Patients with mitral valve prolapse and mitral regurgitation and ruptured chordae tendineae were also significantly older than the unselected subjects with mitral valve prolapse (48 +/- 14 and 55 +/- 16 versus 38 +/- 14 years, p less than 0.005 for both). The concentration of risk of endocarditis in men with mitral valve prolapse and patients with antecedent murmur suggests that antibiotic prophylaxis is warranted in these groups but not in women without a murmur of mitral regurgitation.

Adolescent↗
PubMed1986

Relation between clinical features of the mitral prolapse syndrome and echocardiographically documented mitral valve prolapse.

Mitral valve prolapse, the most common inherited cardiovascular condition, has been associated with a variety of signs, symptoms and electrocardiographic abnormalities, but the true spectrum of the mitral prolapse syndrome remains in doubt because clinical findings often contribute to patient identification and their prevalence in patient groups may be overstated because of ascertainment bias. Accordingly, clinical findings in 88 patients with echocardiographic mitral prolapse were compared with those in 81 of their adult first degree relatives with mitral prolapse (a group free of ascertainment bias) and in two control groups without mitral prolapse: 172 first degree relatives and 60 spouses. Comparison of relatives with and without mitral prolapse demonstrated true associations between mitral prolapse and clicks or murmurs, or both (67 versus 9%, p less than 0.001), thoracic bony abnormalities (41 versus 16%, p less than 0.001), systolic blood pressure less than 120 mm Hg (53 versus 31%, p less than 0.001), body weight 90% or less of ideal (31 versus 14%, p less than 0.005) and palpitation (40 versus 24%, p less than 0.01). In contrast, relatives with mitral prolapse showed no significant increase over normal relatives or spouses without mitral prolapse in prevalence of chest pain, dyspnea, panic attacks, high anxiety or repolarization abnormalities, but these features were all more common in women than in men (p less than 0.01 to less than 0.001). Thus, the true spectrum of the mitral prolapse syndrome encompasses a midsystolic click and late systolic murmur, thoracic bony abnormalities, low body weight and blood pressure and palpitation. Other suggested clinical features, including nonanginal chest pain, dyspnea, panic attacks and electrocardiographic abnormalities, have appeared to be associated with mitral valve prolapse because of ascertainment bias and an erroneous classification of differences between men and women as being due to mitral valve prolapse.

Adolescent↗
PubMed1985

Complex arrhythmias in mitral regurgitation with and without mitral valve prolapse: contrast to arrhythmias in mitral valve prolapse without mitral regurgitation.

Atrial and ventricular arrhythmias were characterized by ambulatory electrocardiography in 31 patients with nonischemic mitral regurgitation (MR), 17 of whom had echocardiographic evidence of mitral valve prolapse (MVP) and 14 of whom had other causes of MR. Frequent and complex arrhythmias were common and equally prevalent in each MR subgroup, whether or not MVP was present. Multiform ventricular ectopy was found in 77% (24 of 31), ventricular couplets in 61% (19 of 31), and ventricular salvos or ventricular tachycardia in 35% (11 of 31) of patients with MR. Arrhythmias in patients with MR were significantly more prevalent than in 63 patients with MVP who had no evidence of MR. Among patients with MVP, excess arrhythmias associated with MR were most striking with respect to frequent ventricular premature complexes (41% with MR vs 3% without MR), multiform ventricular ectopic activity (88% vs 43%), ventricular couplets (65% vs 6%), and ventricular salvos or ventricular tachycardia (35% vs 5%) (p less than 0.005 for each comparison). These data demonstrate that complex arrhythmias are common in patients with nonischemic MR irrespective of etiology, and that these arrhythmias are more strongly associated with hemodynamically important MR than with MVP alone.

Adult↗
PubMed1985

Mitral valve prolapse and hyperthyroidism: effect of patient selection.

Patients with mitral valve prolapse and hyperthyroidism have common symptoms; the most outstanding symptom is palpitation. To determine whether or not common symptoms contributed to the reported association of these conditions, we evaluated 220 patients with symptomatic mitral valve prolapse and 216 first-degree relatives in 72 families; 65 relatives with mitral valve prolapse and 151 relatives without mitral valve prolapse, all greater than or equal to 16 years of age. Thirty subjects, aged 49 +/- 13 years (p less than 0.025 vs entire study group), had thyroid disease (23 subjects had definite thyroid disease, seven subjects had probable); 27 of 30 subjects with thyroid disease (90%) were female (p less than 0.005). The age- and sex-adjusted prevalence of hyperthyroidism was significantly higher in probands with mitral valve prolapse than in family members without mitral valve prolapse (3.5% vs 0%, p = 0.03), while an intermediate prevalence of hyperthyroidism (2.2%) was observed in family members with mitral valve prolapse. Thus, the prevalence of hyperthyroidism is increased among symptomatic patients with mitral valve prolapse as compared to family members without mitral valve prolapse, but the prevalence of thyroid conditions is similar among family members with or without this condition. These findings are explained by the effect of common symptoms on clinical detection of both mitral valve prolapse and hyperthyroidism.

Adolescent↗
PubMed1984

Lack of association between dermal arches and mitral valve prolapse: relation to anxiety.

Mitral valve prolapse (MVP) has been reported to be associated with an increased frequency of dermal arches. To determine whether dermal arches are associated with MVP, 42 patients with echocardiographic (echo) MVP (probands) and 140 first-degree relatives in their families, including 48 with and 92 without MVP, were studied. Seventy-five, subjects with neither MVP nor blood relation to probands served as control subjects. Among the female probands, 6.9% had arches and among the males, 3.8% had arches. The proportion of arches was lower among female control subjects (4.0%) but higher among male control subjects (7.9%) (neither difference being significant [NS]). Among the relatives, 7.1% of the women with MPV and 4.6% of the women without MVP had arches (NS). Five percent of the men with MVP and 6.3% without MVP had arches (NS). No association existed between the occurrence of cardiovascular symptoms in patients and family members with MVP and presence of dermal arches, but a high proportion of probands with elevated trait anxiety without panic disorder had 4 or more dermal arches. These findings do not support a direct association of dermal arches with MVP.

Adolescent↗
PubMed1984

Arrhythmias in mitral valve prolapse. Effect of selection bias.

To assess the contribution of bias in subject selection to the prevalence of arrhythmias in cases of mitral valve prolapse (MVP), we compared ambulatory arrhythmias in 63 patients with MVP and 28 symptom-matched control subjects. All subjects were in sinus rhythm. Mean 24-hour heart rate of the prolapse population was lower than that of the control group (76 v 82 beats per minute). Mean atrial premature complex (APC) density per 1,000 beats (0.9 v 0.7 for patients with MVP and control subjects, respectively) and mean ventricular premature complex (VPC) density per 1,000 total beats (1.2 v 1.5) did not differ between groups. Small differences between groups in APC and VPC complexity did not reach statistical significance. Our findings suggest that, compared with similarly symptomatic controls, patients with MVP do not have as high an excess prevalence of arrhythmias as previously believed.

Adult↗
PubMed1982

Association of mitral-valve prolapse with low body-weight and low blood pressure.

Subjects with mitral-valve prolapse (MVP) have been observed to have an asthenic body build. To determine whether body-weight differed between individuals with inherited MVP and normal subjects, 177 relatives of 45 patients with MVP were studied, 35 female and 19 male relatives had MVP, and 51 female and 72 male relatives did not. There was no difference in mean height between relatives with and without MVP, but those with MVP weighed significantly less. Blood pressure was also significantly lower in relatives with MVP than in normal relatives. It is suggested that the lower blood pressure and the possible beneficial effects of lower weight on other cardiovascular risk factors may provide a selective advantage to carriers of the MVP gene, explaining its high prevalence in the general population. These findings may provide the first example of a common inherited condition which is systematically associated with changes in body-weight and blood pressure.

Adolescent↗
PubMed1982

Inheritance of mitral valve prolapse: effect of age and sex on gene expression.

To ascertain if mitral valve prolapse is inherited we studied 45 probands and 179 first-degree relatives. Echocardiographic mitral prolapse was present in 54 of 179 first-degree relatives (30%); at least one first-degree relative was affected in 29 families, including members of two generations in 23 families. The number of affected persons in the 54 sibships fell within the range predicted for autosomal dominant inheritance. The familial prevalence of prolapse was similar whether or not the proband had characteristic symptoms, auscultatory abnormalities, electrocardiographic findings, thoracic bony abnormalities, or coexistent heart disease. Mitral prolapse occurred in 37 of 90 women (41%) but 17 of 89 men (19%; p less than 0.005), and in 51 of 143 adults (35%) but only 3 of 36 children aged 1 to 15 (p less than 0.005). Mitral valve prolapse is an inherited autosomal dominant condition irrespective of clinical findings, and the mitral prolapse gene shows age and sex dependent expression. Mitral valve prolapse appears to be the commonest mendelian cardiovascular abnormality in humans.

Adolescent↗