Biomedical subjects

A Gopal

Publications and source records attributed to A Gopal.

21 records · Page 2Linked to original sources

PubMed1992

Patent foramen ovale as a risk factor for cryptogenic stroke.

OBJECTIVE: To determine and compare the prevalence of patent foramen ovale in patients with stroke of undetermined origin (cryptogenic) and in patients with stroke of determined origin to assess the possible role of patent foramen ovale as a risk factor for cryptogenic stroke. DESIGN: Cross-sectional study with nested case-control analysis. PATIENTS: A total of 146 patients (73 men, 73 women) with acute ischemic stroke referred to the echocardiography laboratory for evaluation. SETTING: Neurovascular Unit and Echocardiography Laboratory, Columbia-Presbyterian Medical Center, New York, New York. MEASUREMENTS: Patients were considered to have strokes of determined origin or cryptogenic strokes according to National Institute of Neurological Disorders and Stroke (NINDS) Stroke Data Bank criteria. The presence of patent foramen ovale was assessed by contrast echocardiography, performed blinded for type of stroke. The association between patent foramen ovale and type of stroke was tested after correcting for patients' demographic variables and stroke risk factors. RESULTS: The overall prevalence of patent foramen ovale was 26 of 146 patients (18%; 95% Cl, 11.4% to 24.6%). Patients with cryptogenic stroke (31%) had a significantly higher prevalence of patent foramen ovale than did patients with an identifiable cause of stroke (69%) in both the younger (less than 55 years; 48% compared with 4%; P less than 0.001) and the older (greater than or equal to 55 years; 38% compared with 8%; P less than 0.001) age groups. Multiple logistic regression analysis was used to identify the presence of a patent foramen ovale as strongly associated with the diagnosis of cryptogenic stroke (odds ratio, 7.2; Cl, 2.4 to 21.7), irrespective of patient age and other stroke risk factors. CONCLUSIONS: Patients with cryptogenic stroke have a higher prevalence of patent foramen ovale than patients with stroke of determined cause in all age groups, even after correcting for the presence of recognized stroke risk factors. This identifies patent foramen ovale as a risk factor for cryptogenic stroke. Regardless of patient age, contrast echocardiography should be considered when the cause of stroke is unknown.

Adult↗

PubMed1991

Relationship of auscultatory fourth heart sound to the quantitated left atrial filling fraction.

The fourth heart sound (S4) has been associated with vigorous atrial contraction. However, the presence of S4 has not been previously correlated with quantitated left atrial filling fraction. In this study, the presence of an auscultatory S4 was compared with the Doppler echocardiographically quantitated left atrial filling fraction in 41 consecutive patients in whom S4 was judged to be present or absent according to the consensus of cardiologists. Left atrial filling fraction in patients with S4 was 49% and was significantly greater than 33% found in patients without S4 (p less than 0.005). Using atrial filling fraction of 35% as a dividing line, S4 had a sensitivity of 84% and a specificity of 75% for determining left atrial filling fraction greater than or equal to 35%. Furthermore, of 25 patients with S4, 21 (84%) had atrial filling fraction greater than or equal to or less than 35%, and of 16 patients without S4, 12 (75%) had atrial filling fraction less than 35%. Thus, the presence or the absence of S4 is quantitatively related to the left atrial filling fraction and appears to predict atrial filling fraction greater than or equal to or less than 35% reasonably well.

Adult↗

PubMed1991

In vivo effects of nonionic and ionic contrast media on beta-thromboglobulin and fibrinopeptide levels.

Nonionic contrast media are suggested to cause increased thromboembolism (in vivo), platelet aggregation and procoagulant effect (in vitro) as compared with ionic contrast media. To study these effects in vivo, 30 consecutive patients undergoing routine angiography were prospectively randomized to three groups of 10 patients each. Group A received diatrizoate (ionic, high osmolality), Group B ioxaglate (ionic, low osmolality) and Group C iohexol (nonionic, low osmolality). In vivo platelet alpha-granule release and fibrin-1 formation were measured by radioimmunoassay of beta-thromboglobulin and fibrinopeptide A in peripheral venous samples. Levels were estimated at three stages during the procedure: before and after left ventriculography and after coronary angiography. No differences were noted (p = NS) when the ratios of beta-thromboglobulin and fibrinopeptide A were compared among the three groups. These data suggest that the newer nonionic contrast media do not demonstrate enhanced systemic platelet activation or fibrin formation as compared with standard ionic contrast media. However, larger randomized clinical studies are necessary to conclusively establish the suggested thromboembolic potential of nonionic contrast media.

Angiography↗