Mandatory computer field for blood pressure measurement improves screening.

METHODS: We evaluated the effectiveness of a compulsory data field in a computerized medical record (CMR) in improving blood pressure (BP) screening. RESULTS: The proportion of study patients who had their BP measured increased from 40.6% to 58.5% (P < 0.001) after the intervention. After adjusting for age, gender and number of visits, patients were 73% more likely to have their BP recorded after the introduction of the compulsory field.

Exercise blood pressure response is related to left ventricular mass.

An exaggerated SBP response to exercise has been associated with increased left ventricular (LV) mass in some but not all studies. A total of 43 women and 34 men, aged 55-75 years, without evidence of cardiovascular disease, with a mean resting BP of 142+/-9/77+/-8 mmHg had their BP measured at rest and during maximal treadmill exercise. LV mass was measured using magnetic resonance imaging. LV mass was adjusted for lean body mass, which was assessed by dual energy X-ray absorptiometry. LV mass was within the normal range for the majority of the subjects. Among the resting and exercise BP indices, maximal SBP was the strongest correlate of LV mass (r=0.41, P<0.05). In multivariate analysis, maximal SBP was independently associated with LV mass after adjustment for lean body mass and gender, explaining 3% of the variance (P<0.05). Maximal exercise SBP is a modest but still independent predictor of LV mass in older persons with normal LV mass. These results raise the possibility that the SBP response to maximal exercise is an early marker of LV hypertrophy.

The relationship between vascular wall shear stress and flow-mediated dilation: endothelial function assessed by phase-contrast magnetic resonance angiography.

OBJECTIVES: We sought: 1) to investigate the relationship between vascular wall shear stress and flow-mediated dilation (FMD) in humans, and 2) to investigate whether this relationship could explain why FMD is greater in small arteries. BACKGROUND: Arterial wall shear stress (WSS) is considered to be the primary stimulus for the endothelial-dependent FMD response. However, the relationship between WSS and FMD has not been investigated in humans. Furthermore, FMD is greater in small arteries, though the reasons for this phenomenon are unclear. METHODS: Using phase-contrast magnetic resonance angiography (PMRCA), we measured hyperemic WSS and FMD in 18 healthy volunteers. Peak systolic WSS was calculated assuming a blunted parabolic velocity profile. Diameter by PCMRA and by ultrasound was compared in nine subjects. RESULTS: Flow-mediated dilation was linearly proportional to hyperemic peak systolic WSS (r = 0.79, p = 0.0001). Flow-mediated dilation was inversely related to baseline diameter (r = 0.62, p = 0.006), but the hyperemic peak WSS stimulus was also inversely related to baseline diameter (r = 0.47, p = 0.049). Phase-contrast magnetic resonance angiography and ultrasound diameters were compared in nine subjects and correlated well (r = 0.84, p < 0.0001), but diameter by PCMRA was greater (4.1 +/- 0.7 mm vs. 3.7 +/- 0.5 mm, p = 0.009). CONCLUSION: Arterial FMD is linearly proportional to peak hyperemic WSS in normal subjects. Thus, the endothelial response is linearly proportional to the stimulus. Furthermore, the greater FMD response in small arteries is accounted for, at least partially, by a greater hyperemic WSS stimulus in small arteries. By allowing the calculation of vascular WSS, which is the stimulus for FMD, and by imaging a fixed arterial cross-section, thus reducing operator dependence, PCMRA enhances the assessment of vascular endothelial function.

A comparison of prospective and retrospective respiratory navigator gating in 3D MR coronary angiography.

A comparison between the prospective and retrospective respiratory navigator gating in MR coronary angiography was performed with eight normal subjects. A three-dimensional (3D) ECG-gated fast gradient echo pulse sequence was used for image data acquisition. The results show that the MR coronary angiography obtained using retrospective gating retains a considerable amount of motion artifacts. In this study, the images acquired using prospective navigator gating demonstrated significantly reduced motion artifacts (p = 0.009), improved vessel visibility (p = 0.021) with reduced imaging time (p = 0.013) compared to the images obtained using retrospective navigator gating.

The association of resting heart rate with cardiovascular, cancer and all-cause mortality. Eight year follow-up of 3527 male Israeli employees (the CORDIS Study)

BACKGROUND: Resting heart rate has frequently been shown to be a predictor of coronary heart disease mortality. Elevated heart rate could also be a marker for the presence of other risk factors, which have not been taken into consideration in previous studies. OBJECTIVE: To evaluate the effect of resting heart rate on the risk of all-cause cardiovascular and cancer mortality, taking into consideration haematological variables. METHOD: The association between resting heart rate and mortality was assessed applying Cox's proportional hazard models to data obtained in an 8 year follow-up of 3527 Israeli male industrial employees. During this period 135 deaths were recorded, 57 from cardiovascular disease and 45 from cancer. Resting heart rate was assessed at entry; potential confounding demographic, anthropometric and socioeconomic variables, haematological data, serum lipid levels and health-related habits were accounted for. RESULTS: We found that the relative risk of all-cause mortality increased with increasing resting heart rate, workers with resting heart rate >90 beats. min(-1)had an adjusted relative risk of 2.23 (95% CI 1.4-3.6) compared with those with a heart rate <70 beats. min(-1). A similar result was achieved for cardiovascular disease mortality (adjusted relative risk 2.02, 95% CI 1.1-4.0). Cancer mortality was not associated with resting heart rate. CONCLUSION: This study found that resting heart rate is associated with all-cause and cardiovascular disease mortality after controlling (in various statistical models) for platelet counts, haemoglobin concentration, white blood cell counts, total protein, and other recognized risk factors.

Spectrophotometric studies of complexation of C60 with aromatic hydrocarbons.

The equilibrium constants for complexation of C60 with naphthalene, phenanthrene and pyrene in toluene have been determined by UV visible spectroscopy. The magnitude of the equilibrium constants was found to increase with decreasing ionization potential of the donor. Values for complexation enthalpy have been determined for the first time for C60/aromatic hydrocarbons. Well-defined charge transfer (C-T) bands have been observed for complexes of C60 with a variety of aromatic hydrocarbons, with C-T band maxima moving to higher frequency with increasing donor ionization potential.

Exercise blood pressure changes between seasons.

BACKGROUND: Blood pressure (casual and daytime) is higher in winter than it is in summer, and this factor might be partly responsible for the higher cardiovascular mortality in winter. OBJECTIVE: To determine in a prospective study whether there is also a seasonal variation in exercise blood pressure. METHODS: We evaluated the pretest, exercise (five-step treadmill test) and recovery values of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate of 94 healthy men, aged 20-65 years, during the summer and winter. RESULTS: SBP and DBP values were higher in winter than they were in summer during the resting period immediately before exercise (P = 0.003 and P = 0.07, respectively), and during recovery (both P < 0.0001). Exercise SBP and heart rate values were similar in the two seasons, although exercise DBP was higher in winter than it was in summer (P < 0.0001). The increase in DBP from pretest to stage 3 was 6.5 mmHg in summer and 10.4 mmHg in winter (P = 0.002). After we had controlled for possible confounders, the increase in DBP during exercise was found to be independently associated with season of the year and resting DBP. CONCLUSIONS: Exercise DBP varies according to season whereas exercise SBP does not. Our results suggest that, since measures of the response of blood pressure to exercise testing are frequently used in blood pressure and hypertension research as well as in clinical practice, the seasonal influences should be taken into account.

Findlay implantable two-stage centrifugal pump.

The Findlay centrifugal pump is unique in its two-stage pumping mechanisms and in its complementary interrelationship of the stages to each other and to the exit system, and it forms an extremely efficient unit. The first stage is a lift force pump as an inlet. The second and major stage is a shear force pump. Twenty-six prototypes, many multiply modified, have been hand fabricated, and most have had classic pump function analyses. Six pumps have demonstrated minimal hemolysis (3.5-5 h). At modest rotation speeds, it pumps water up to 10 L/min. Forty-four acute studies in normal dogs have been performed with the Findlay pump in a ventricular assist system. Blood flows through the pump ranged from 1.2 to 4.5 L/min. The conclusion is that the Findlay pump has the ability to operate with low blood damage, performs at acceptable rotational speed with reasonable hydraulic and mechanical efficiency, and is small and implantable.

Incremental value of simultaneous assessment of myocardial function and perfusion with technetium-99m sestamibi for prediction of extent of coronary artery disease.

OBJECTIVES: This study assessed the incremental value of technetium-99m myocardial single-photon emission computed tomography (SPECT) and simultaneous first-pass radionuclide angiography, when added to treadmill exercise, for prediction of the extent of coronary artery disease. BACKGROUND: Technetium-99m count statistics permit the simultaneous assessment of myocardial perfusion and function. However, whether this characteristic improves prediction of the extent of coronary artery disease remains unknown. METHODS: We studied 70 consecutive patients who had coronary angiography within 6 months of the scintigraphic study. All patients underwent a symptom-limited treadmill exercise test. Treadmill data were summarized using a previously validated score. Left ventricular ejection fraction and regional wall motion were evaluated from a first-pass radionuclide angiogram acquired at peak treadmill exercise in the anterior view. Perfusion was assessed visually. Extent of angiographic disease was expressed as the presence or absence of multivessel disease (more than two coronary artery territories with > 50% stenosis) and as a score that reflects the location of severe (> 75%) stenosis. RESULTS: Stepwise addition of scintigraphic data (perfusion first, followed by function) to the treadmill score showed significant incremental value for prediction of the angiographic score at each step; exercise ejection fraction alone was the strongest independent predictor. Discriminant accuracy for detection of multivessel disease was also improved by the addition of perfusion information to the treadmill score and addition of regional wall motion analysis to both of them. In this case, ejection fraction failed to show independent value. CONCLUSIONS: The addition of simultaneously performed sestamibi perfusion SPECT and first-pass radionuclide angiography to the treadmill exercise test significantly improved prediction of the extent of coronary artery disease.

The prognostic importance of two easily obtainable noninvasive markers after intravenous thrombolytic therapy in acute myocardial infarction.

The predictability of left ventricular function, short- and long-term prognosis, assessed by means of two easily obtainable noninvasive markers, was prospectively studied in 110 consecutive patients undergoing thrombolytic therapy for acute myocardial infarction. Positive noninvasive markers were defined as follows: a) > 50% reduction in ST segment elevation within 120 min of initiating therapy, and b) early peak of creatine kinase (CK) activity < 12h after the start of thrombolysis. Seventy-five (68%) of the patients had two positive markers and are classified as the responder group. The nonresponder group consisted of 35 patients (32%) who had 0-1 positive markers. Left ventricular function was assessed 6-12 weeks after therapy by equilibrium radionuclide ventriculography. Left ventricular ejection fraction (LVEF) and survival rates at 1 month and 36 months were significantly higher in the responder group compared to the nonresponder group (54 +/- 12% vs. 43 +/- 11%, P < 0.05; 99% vs. 89%, P < 0.06; and 95% vs. 80%, P < 0.05 respectively). Thus, the combined analysis of two easily obtainable noninvasive markers can predict post-treatment preservation of left ventricular function and survival up to 36 months in patients with acute myocardial infarction undergoing thrombolytic therapy.

The St. Jude valve. Thrombolysis as the first line of therapy for cardiac valve thrombosis.

BACKGROUND: Thrombolytic therapy is a promising alternative to valve replacement in the management of prosthetic valve thrombosis. We sought to determine the short- and long-term results of treating thrombosed St. Jude heart valves with thrombolytic therapy as the primary treatment modality. METHODS AND RESULTS: Between March 1978 and December 1991, 988 patients underwent implantation of St. Jude prosthetic valves at our medical center, and all patients with thrombosed valves were identified prospectively. During this period, 17 patients (13 women; mean age, 66.8 +/- 19.0 years) developed prosthetic valve thrombosis (11 aortic, six mitral). In six patients, Coumadin was stopped in preparation for elective surgery. The clinical presentation was congestive heart failure in 13, syncope and fatigue in two, and a cerebrovascular accident in one; one patient was asymptomatic. The average duration of symptoms was 11.7 +/- 12.0 days (range, 1-45 days). Anticoagulation was subtherapeutic in all but one patient at the time of presentation. Cinefluoroscopy was the primary method used for diagnosis and was also used to follow the response to therapy. Twelve patients were treated medically (10 with thrombolytic therapy and two with heparin), three were treated surgically, and two were diagnosed at autopsy. Of the 12 medically treated patients, 10 had marked improvement in leaflet movement and symptoms within 12 hours. Thus, 10 of 12 patients (83%) had a satisfactory response to medical therapy alone. No medically treated patient died or had a major complication resulting in permanent damage. However, four of the 12 medically treated patients had minor complications, including a transient episode of facial weakness in one patient, hematomas in two, and epistaxis in one. Late rethrombosis recurred in two patients in the medically treated group and was successfully retreated with thrombolytic therapy. At 3 months, all patients were alive and well. CONCLUSIONS: Thrombolytic therapy can be used as the first line of therapy for thrombosed St. Jude valves with a low risk of permanent side effects and excellent chances of success. In most cases, surgery can be reserved for patients who do not respond to thrombolytic therapy.

Short- and long-term comparative study of anistreplase versus streptokinase in acute myocardial infarction.

Streptokinase is well established as an effective thrombolytic. Anistreplase, a new thrombolytic drug, is a complex of streptokinase and acylated human plasminogen that can be administered by intravenous bolus and activates plasminogen at the clot site. Although both streptokinase and anistreplase are effected in treating myocardial infarction (MI), they have different pharmacologic properties. This study was designed to identify short- and long-term differences in their clinical effectiveness, safety in use, and survival rates in patients with acute MI. One hundred ten successive patients under seventy years of age admitted within three hours after onset of sustained chest pain suggestive of acute MI were randomized to receive either 30 units of anistreplase intravenously over five minutes or intravenous injection of 750,000 units of streptokinase over thirty to sixty minutes. Reperfusion was achieved in 34 of the 52 (65%) patients treated with anistreplase and in 41 of the 58 (71%) patients treated with streptokinase (p = NS). The two drugs were equally effective in preserving left ventricular ejection fraction, which was found to be significantly better in patients with anterior wall MI who had achieved reperfusion than it was in those who did not (p less than 0.02). One-month, twelve-month, and thirty-six-month survival rates were high (96% to 88%) with no significant difference between the two treatment groups. The authors conclude that the two drugs are equally effective thrombolytic agents but that anistreplase has the advantage that it can be administered as a bolus injection.

Improved left ventricular function in myocardial infarction following intravenous thrombolytic therapy with acylated plasminogen activator.

Forty-six patients with acute myocardial infarction (MI) were treated within three hours of the onset of chest pain with an intravenous bolus (IV) of 30 units of anisolated plasminogen activator streptokinase complex (APSAC). Reperfusion was detected in 31 patients (67%) by clinical, electrocardiographic, and enzymatic criteria. The mean time elapsed between the onset of the chest pain to thrombolytic therapy was 114 +/- 53 minutes. Left ventricular ejection fraction (LVEF) was significantly better in patients with anterior and inferior myocardial infarction who had successful reperfusion, as compared with those who did not (48.8 +/- 13.0 vs 35.3 +/- 10.9, p less than 0.05 and 59.7 +/- 12.6 vs 47.9 +/- 15.3, p less than 0.05, respectively). The rate of reocclusion within three weeks was 22%. The overall one-year mortality was 4%. There were no serious adverse reactions following the thrombolytic treatment. Thus bolus IV injection of 30 units of APSAC is both safe and effective in preserving left ventricular function when given early in the course of acute myocardial infarction.