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Biomedical subjects

V Karttunen

Publications and source records attributed to V Karttunen.

7 recordsLinked to original sources
PubMed2002

Risk factors for cryptogenic ischaemic stroke.

This case-control study was designed to identify risk factors for cryptogenic brain infarction. We assessed the frequency of prothrombotic states, homocysteine, lipoprotein (a) [Lp(a)] and other lipids and the apolipoprotein E phenotype together with conventional risk factors in 46 patients (19 women and 27 men) with cryptogenic brain infarction aged from 15 to 60 years and in 104 community-based controls. Multivariate odds ratios (ORs) for risk factors and 95% CIs were calculated by logistic regression. Hypertension (OR 4.5; 95% CI, 1.5-13.2; P = 0.006), current smoking (OR 2.9; 95% CI, 1.2-6.8; P = 0.012), low HDL cholesterol (HDL-C) (OR 5.4; 95% CI, 1.1-25.5; P = 0.035) and high clotting factor VIII activity (OR 3.6; 95% CI, 1.1-12.2; P = 0.041) were variables associated with cryptogenic brain infarction. These risk factors were not equally frequent in women and men. Low HDL-C and high factor VIII activity in the women, and hypertension, current smoking and a low level of plasma folate in the men were risk factors for cryptogenic stroke. Several of the observed risk factors for cryptogenic brain infarction were lifestyle-associated, which emphasizes the role of health education in addition to pharmacological treatment in the prevention of stroke.

Adolescent↗
PubMed2001

Ear oximetry: a noninvasive method for detection of patent foramen ovale: a study comparing dye dilution method and oximetry with contrast transesophageal echocardiography.

BACKGROUND AND PURPOSE: Patent foramen ovale (PFO) may play an important role as a risk factor for ischemic stroke and some other neurological conditions. There is a need for low-cost and noninvasive methods for the detection of PFO. This study evaluates the accuracy of two simple bedside tests, the dye dilution method and ear oximetry, in the detection of PFO. METHODS: Dye dilution curves and ear oximetry recordings with a noninvasive ear densitometer were obtained from consecutive cryptogenic stroke patients referred for contrast transesophageal echocardiography (TEE). All test results were blindly assessed for the presence of PFO. Sensitivity and specificity were calculated with TEE used as a reference method. kappa statistics were used to measure interrater agreement. RESULTS: Dye dilution curves were obtained from 67 patients. Dye dilution correctly diagnosed 35 of the 46 patients who had PFO in TEE and all the 21 patients without PFO. Thus, the sensitivity (95% CI) of the dye dilution method was 76% (61% to 87%) and its specificity 100% (84% to 100%). Ear oximetry was done on 83 patients. Oximetry correctly diagnosed 45 of the 53 patients who had PFO in TEE and all of the 30 patients without PFO. Thus, the sensitivity of ear oximetry was 85% (72% to 93%) and its specificity 100% (88% to 100%). The interrater agreement was excellent (kappa value 0.94 for dye dilution and 0.90 for oximetry). CONCLUSIONS: Dye dilution and oximetry are both sensitive and specific methods for the detection of PFO. Oximetry has the following primary advantages over the currently available diagnostic methods: it is noninvasive, safe, and inexpensive and causes no discomfort for the patient. We suggest that oximetry could be used as a first-line screening method for PFO in patients with cryptogenic stroke. Ear oximetry also has potential use in epidemiological studies.

Adult↗
PubMed1998

Mechanisms of alcohol-related strokes.

Epidemiological investigations have shown a linear positive correlation between the risk of haemorrhagic stroke and level of alcohol consumption. Ischaemic stroke shows a weaker relationship, which is J-shaped, suggesting that regular light-to-moderate alcohol consumption may carry a decreased risk. Case reports and case-control studies indicate that heavy recent drinking, but not heavy former drinking, increases the risk for both types of stroke. Larger amounts of alcohol are needed to trigger aneurysmal subarachnoid haemorrhage than spontaneous intracerebral haemorrhage. The increased risk caused by recent heavy drinking may be partly due to elevated systolic blood pressure, but alcohol may also provoke cerebral arterial vasospasm, as observed in animal experiments. Alcohol-induced fluctuation in haemostatic and fibrinolytic factors has not been proved to precipitate alcohol-related strokes, but may contribute to both an increase and a decrease of the risk. Subtypes of ischaemic stroke associate differently with alcohol consumption. A recent series of patients with ischaemic brain infarction showed that of the victims having a high and medium risk for cardiogenic embolism, 50% and 45% were intoxicated, respectively. This suggests that cardiogenic embolism is a significant mechanism leading to ischaemic stroke during heavy drinking of alcohol.

Adult↗
PubMed1998

Dye dilution and oximetry for detection of patent foramen ovale.

OBJECTIVES: Patent foramen ovale (PFO) is a risk factor for stroke of undetermined (cryptogenic) origin. Low cost and non-invasive bedside tests for detection of PFO are needed as alternatives to contrast transesophageal echocardiography. We investigated whether dye dilution curves and oximeter recordings are useful for detecting PFO and what is the prevalence of PFO in patients with cryptogenic stroke determined with these bedside methods. We also studied whether stroke risk factors, number of brain lesions, and stroke recurrence rates were different in patients with an unexplained stroke with and without PFO. MATERIAL AND METHODS: Dye dilution curves and oximeter recordings with non-invasive earpiece apparatus were obtained in 59 patients aged under 50 years who had had a cryptogenic brain infarction. The number of ischemic lesions in the brain was counted by MRI. RESULTS: PFO was found in 24 (41%) of 59 patients. There was a 100% concordance in results obtained by dye dilution and by oximetry. Risk factors for stroke were similar in subjects with PFO and those without PFO. No significant association was found between PFO and Valsalva-like activity at stroke onset. Those with PFO did not have more ischemic lesions detected by MRI nor did they have more recurrent ischemic episodes. CONCLUSION: Dye dilution and oximetry are cheap and useful methods for detection of PFO and could be used for screening of the risk of paradoxical embolism. Because these 2 methods were not compared with the golden standard, transesophageal echocardiography, the specificity and sensitivity of the tests remain unsettled.

Adolescent↗