Biomedical subjects

Roger Marx

Publications and source records attributed to Roger Marx.

4 recordsLinked to original sources

PubMed2003

Recurrent syncope in a young patient with long QT syndrome: possible relationship of atrioventricular nodal re-entrant tachycardia with neurally mediated spells?

This is a case of a 15-year-old woman with long QT syndrome (LQTS) and a history of 14 events of syncope, demonstrating that the underlying mechanism for any symptomatic episode is not necessarily based on torsades de pointes. The need for careful distinction between true ventricular tachyarrhythmia and other forms of supraventricular tachycardia in the LQTS is the subject of the article. To the knowledge of the authors, this is the first reported case of an association of LQTS with AV nodal re-entrant tachycardia.

Adolescent↗

PubMed2002

C/T polymorphism of the intercellular adhesion molecule-1 gene (exon 6, codon 469). A risk factor for coronary heart disease and myocardial infarction.

BACKGROUND: The intercellular adhesion molecule-1 (ICAM-1) mediates the interaction of activated endothelial cells with leukocytes and plays a fundamental role in the pathogenesis of coronary atherosclerosis. ICAM-1 single-base C/T polymorphism, which determines an amino acid substitution in the ICAM-1 protein in exon 6 codon 469, has been described. Our purpose was to determine whether this C/T polymorphism influences the risk of coronary heart disease (CHD) and myocardial infarction (MI) in humans. METHODS AND RESULTS: We enrolled 349 patients with angiographically documented CHD, including a sub-group of 179 patients with acute or chronic MI. The control group consisted of 213 patients with normal left ventricular function and no documented evidence of CHD. All patients and controls were Germans genotyped by polymerase chain reaction and allele-specific oligonucleotide techniques for the ICAM-1 polymorphism. In the patients with CHD and MI the frequencies of the T genotype (TT+TC) were significantly higher than the CC genotype compared to the control subjects (P<0.001). With the additional use of multivariable logistic regression analysis for CHD (TT+TC versus CC; P=0.011, odds ratio 2.21, 95% CI 1.20-4.07), we found a significant association between CHD and MI and the TT and TC genotype of the ICAM-1 gene polymorphism. CONCLUSIONS: These results suggest that the TT and TC genotype of the ICAM-1 gene polymorphism in codon 469 is a genetic factor that may determine an individual's susceptibility for CHD and MI.

Aged↗

PubMed2002

Left ventricular diastolic function in physiologic and pathologic hypertrophy.

BACKGROUND: Patients with hypertensive heart disease and left ventricular hypertrophy demonstrate an impaired left ventricular diastolic filling pattern. The aim of this study was to find out whether physiologic left ventricular hypertrophy induced by endurance training causes disturbances in left ventricular systolic and diastolic filling. METHODS: We examined 49 athletes with left ventricular (LV) hypertrophy due to endurance training, 49 patients with LV hypertrophy due to arterial hypertension, and 26 untrained healthy control subjects by conventional echocardiography. Parameters of LV diastolic filling using pulse wave and color flow Doppler were also assessed. RESULTS: All three study groups showed normal fractional shortening and mid-wall fractional shortening. Conventional echocardiography revealed a higher LV muscle mass index in the two study groups compared with the controls (athletes, 99 +/- 10 g; hypertensive patients, 95 +/- 11 g: controls: 52 +/- 7 g; P < .01 for athletes and hypertensive patients). In patients with arterial hypertension, a diastolic dysfunction consisting of a delayed relaxation pattern with a decrease in maximal early velocity of diastolic filling (0.44 +/- 0.1 m/sec) and a compensatory increase of the maximal late velocity of diastolic filling (0.53 +/- 0.1 m/sec) was demonstrated. In athletes with physiologic LV hypertrophy, a normal LV diastolic filling pattern was documented. CONCLUSIONS: Doppler echocardiographic parameters of LV diastolic function can be of diagnostic importance for discrimination between pathologic and physiologic LV hypertrophy.

Adult↗

PubMed2002

Left ventricular hypertrophy and diastolic dysfunction in healthy pregnant women.

OBJECTIVE: The purpose of this study was to examine which hemodynamic parameters change under the natural volume overload of pregnancy. STUDY DESIGN: 46 healthy pregnant women were echocardiographically examined during the course of pregnancy. To evaluate left ventricular diastolic function, mitral inflow and pulmonary venous flow profiles were used. Fractional shortening and left ventricular muscle mass were calculated. RESULTS: In the course of pregnancy the left ventricular muscle mass index increased (from 66 +/- 6 to 96 +/- 9 g/m(2)), fractional shortening decreased (from 38 +/- 4 to 32 +/- 6%) and a disturbed diastolic relaxation pattern was documented. Eight weeks after delivery, all left ventricular systolic and diastolic functional parameters returned to normal values. CONCLUSION: The natural volume overload in pregnancy leads to a reversible 'physiological' left ventricular hypertrophy, a short-term decrease in systolic function and a significant change in left ventricular diastolic function.

Adult↗