Mean Difference In Systolic Pressure Research Articles

Co-Loading Versus Pre-Loading for Preventing Post-Spinal Hypotension in Caesarean Section

Co-Loading Versus Pre-Loading for Preventing Post-Spinal Hypotension in Caesarean Section

COMPARATIVE EVALUATION OF ACCURACY OF RECORDING BLOOD PRESSURE EITHER BY AUTOMATED OSCILLOMETRIC METHOD OR BY SPHYGMOMANOMETER IN BOTH NORMOTENSIVE AND HYPERTENSIVE PATIENTS - A PROSPECTIVE OBSERVATIONAL STUDY

Objectives: Automatic devices based on oscillometric principle are widely used for the estimation of blood pressure (BP). Mercury sphygmomanometer mean systolic BP (MSBP) and its derived cuff pressure are the traditional mode of estimation which is a validated and authenticated procedure. Automated machines using oscillometric method are slowly replacing the conventional technique. This study was done to compare the BP recorded by the mercury sphygmomanometer MSBP and the automated technique using oscillometric method automated office BP (AOBP).Methods: Two hundred subjects aged 40–65 years with mid-arm circumference 27–34 cm were recruited. MSBP and AOBP were recorded adhering to guidelines given by the American Heart Association Joint National Committee. The subjects were divided into two groups as normotensive (Group 1) and hypertensive (Group 2), and statistical analysis was performed.Results: The mean systolic and diastolic pressures estimated by oscillometric method and sphygmomanometer were calculated and compared with each other by paired t-test separately for Groups 1 and 2. In mormotensives (Group 1), the mean systolic pressure MSBP was 114.21±7.5 mmHg and AOBP was 118.24±11.0 mmHg. The mean diastolic MSBP was 72.1±3.5 mmHg and AOBP was 76.4±1.2 mmHg. Subjects of Group 2 (hypertensive) showed mean systolic pressure MSBP of 144.42±18.5 mm Hg and AOBP of 159.74±22 mmHg. The mean diastolic MSBP was 87.2±9.5 mmHg and AOBP was 96.9±9.2 mmHg. In Group 1, the difference was statistically not significant, while in Group 2, comparison by paired t-test showed a mean difference of systolic pressure by 15.32±1.25 (p<0.005), and mean difference of diastolic pressure by 8.9±5.8 (p<0.005).Conclusion: Hence, we conclude that oscillometric pressure recordings by the automated device are closer to manual measurements in normotensives but showed a significant high value in hypertensives. We suggest caution in treating hypertensives with values derived from automated machines only.

Does Antihypertensive Drug Therapy Decrease Morbidity or Mortality in Patients With a Hypertensive Emergency?

MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and references in review articles were searched. The authors also attempted to identify the grey literature by contacting trialists. Randomized controlled trials that enrolled patients with hypertensive emergencies in which a selected antihypertensive agent was compared with placebo, no treatment, or another drug in a different class. Fifteen randomized controlled trials with 869 patients met the inclusion criteria. Two reviewers extracted data from the included studies and selected studies independently. Discrepancies were resolved by discussion or a third reviewer. Primary outcome measures were total serious adverse events, all-cause mortality, and composite of nonfatal cardiovascular events (ie, unstable angina, aortic dissection, acute renal failure, stroke, respiratory failure). Secondary outcome measures were weighted mean difference in systolic pressure, diastolic blood pressure, pulse rate, and withdrawal because of adverse events. The adequacy of concealment and blinding was assessed.

A Randomized Controlled Trial of the Safety and Promise of Cognitive-Behavioral Therapy Using Imaginal Exposure in Patients With Posttraumatic Stress Disorder Resulting From Cardiovascular Illness

We investigated the physical safety of cognitive-behavioral therapy (CBT) utilizing imaginal exposure in patients who suffered from posttraumatic stress disorder (PTSD) following a life-threatening cardiovascular event. In this phase I, prospective, single-blind trial conducted from April 2006 through April 2008, we randomly assigned 60 patients to receive either 3 to 5 sessions of imaginal exposure therapy (experimental group) or 1 to 3 educational sessions only (control group). Criteria for PTSD and other mental health disorders were evaluated according to DSM-IV using the full Structured Clinical Interview for DSM-IV (SCID). Safety assessments included patients' blood pressure and pulse before and after each study session and the occurrence of deaths, hospitalizations, repeat myocardial infarctions, or invasive procedures. We also investigated the effects of the treatment on PTSD symptoms (Impact of Event Scale and Posttraumatic Stress Disorder Scale), depression (Beck Depression Inventory-II), and the Clinical Global Impressions-Severity of Illness (CGI-S) scale. There were no significant differences between the experimental and control groups and between exposure and nonexposure sessions in any of the safety measures. In addition, confidence intervals were such that the nonsignificant effects of exposure therapy were not of clinical concern. For example, the mean difference in systolic pressure between control and exposure sessions was 0.5 mm Hg (95% CI, -6.1 to 7.1 mm Hg). Nonsignificant improvements were found on all psychiatric measures in the experimental group, with a significant improvement in CGI-S in the entire cohort (mean score difference, -0.6; 95% CI, -1.1 to -0.1; P = .02) and a significant improvement in PTSD symptoms in a subgroup of patients with acute unscheduled cardiovascular events and high baseline PTSD symptoms (mean score difference, -1.2; 95% CI, -2.0 to -0.3; P = .01). Cognitive-behavioral therapy that includes imaginal exposure is safe and promising for the treatment of posttraumatic stress in patients with cardiovascular illnesses who are traumatized by their illness. clinicaltrials.gov Identifier: NCT00364910.

Home blood pressure monitoring improves blood pressure control

QuestionDoes home monitoring improve blood pressure control in people with hypertension?Study designSystematic review with meta-analysis.Main resultsEighteen randomised controlled trials met inclusion criteria (13 reported systolic blood pressure; 16 reported diastolic blood pressure; three reported mean arterial pressure; and six reported blood pressure above target). Blood pressure self-monitoring at home, or monitoring by a family member significantly reduced blood pressure compared with usual monitoring in healthcare settings (see results table). Adjusting for publication bias reduced this difference (mean difference in systolic pressure: 2.2 mmHg, 95%CI −0.9 to 5.3; mean difference in diastolic pressure: 1.9 mmHg, 95%CI 0.6 to 3.2). At 1 year, the relative risk of having blood pressure above the target was lower in people who were monitoring themselves at home compared with people monitored in the healthcare system (RR 0.9, 95%CI 0.8 to 1.0).Authors’ conclusionsHome blood pressure monitoring improves blood pressure more than monitoring in the healthcare system in people with hypertension.

A synthetic fiber-reinforced stentless heart valve

There is strong evidence that failure of bioprosthetic and synthetic valves occurs as a consequence of high tensile and bending stresses, acting on the leaflets during opening and closing. In stented prostheses, whether synthetic or biological, the absence of contraction of the aortic base causes the leaflets to be subjected to an unphysiological degree of flexure, which is also related to calcification. However, a stentless synthetic valve, which has a flexible aorta base, can be a good alternative for stented synthetic valves. Moreover, fiber-reinforcement is assumed to lead to a decrease of tears and perforation as a result of reduced stresses in the weaker parts of the leaflets in their closed configuration. The manufacturing method for a stentless, fiber-reinforced, synthetic valve is presented. Prototypes are tested in a pulse duplicator system. The results show that the mean systolic pressure difference is very low, while the high regurgitation (up to 26%) is probably caused by a too small coaptation area of the leaflets.

In vitro comparison of aortic heart valve prostheses: Part 1: Mechanical valves

The hydrodynamic performance of a series of mechanical heart valve prostheses is measured in the aortic position. All experiments are performed in an electrohydraulic, computer-controlled pulse duplicator simulating the left side of the human circulatory system. Testing conditions are set according to a Food and Drug Administration interlaboratory comparison protocol with cardiac outputs of 3.0, 4.5, 6.5, and 8.0 L/min at a constant heart rate of 70 beats/min. Mean systolic pressure differences, volume losses, and energy losses, as well as dimensionless pressure losses and energy loss coefficients, are calculated from the recorded pressure, volume, and flow tracings. The results of 10 mechanical heart valve prostheses (eight tilting disc valves and two bileaflet valves) are presented and their clinical relevance is discussed.

Haemodynamic evaluation of the convexo-concave Björk-Shiley prosthesis in patients with narrow aortic annulus.

A late haemodynamic re-evaluation at rest and during exercise was performed in 22 patients with isolated aortic valvular disease and narrow aortic annulus, operated upon with the convexo-concave Björk-Shiley prosthesis. The 21 mm prosthesis had been inserted in 11 patients and the 23 mm one in the other 11 patients. Left ventricular pump function improved and was normalized in half of the patients. The mean systolic pressure difference across the 21 mm convexo-concave prosthesis was 16.2 +/- 8.1 mmHg at rest and 20.7 +/- 7.9 mmHg during exercise (32 +/- 10 watts). It was 14.9 +/- 6.0 mmHg at rest and 18.6 +/- 6.3 mmHg during exercise (34 +/- 156 watts) across the 23 mm convexo-concave prosthesis. Compared with the earlier investigated standard model Björk-Shiley prosthesis, the 21 mm convexo-concave version creates a lower resistance to blood flow (less than 0.01), whereas no such difference could be demonstrated in the two models of 23 mm tissue diameter. It was concluded that the new convexo-concave tilting disc valve constitutes an improvement over the standard model in the management of the narrow aortic annulus permitting insertion of a 21 mm prosthesis.

Aortic Valve Replacement. A Randomized Study Comparing the Björk–Shiley and Lillehei–Kaster Disc Valves.Late Haemodynamics Related to Clinical Results

In this study, 78 randomized patients with either Björk-Shiley (B-S) or Lillehei-Kaster (L-K) aortic disc valve prostheses were re-admitted for clinical and haemodynamic evaluation. The patients were selected that those with narrow aortic roots were over-represented. Cine-aortography was carried out in 75 patients and left ventricular catheterisation via the transseptal approach was performed in 42. The clinical improvement was striking, although the number of patients still incapacitated was relatively large in patients with the small L-K valves (Nos. 14 & 16). Peak-to-peak and mean systolic pressure differences across the valves were significantly lower in the B-S than in the L-K valves, particularly when the small valve sizes were compared. Left ventricular end-diastolic pressure (LVEDP), which was elevated in most patients before operation, decreased significantly to normal levels in the B-S group. In the L-K group, LVEDP did not decrease significantly and was on the average still above the normal level after operation, probably due to the relatively large pressure gradients. The study indicates that the L-K valves Nos. 14 & 16 in particular represents a resistance to flow that is too large to be acceptable in clinical practice.

Transatrial resection of the obstructed right ventricular infundibulum.

Obstructions of the right ventricular infundibulum were resected through the orifice of the tricuspid valve in 21 patients, 15 of whom had tetralogy of Fallot. At operation the systolic pressure difference between the right ventricle and pulmonary artery after repair averaged 18 mm Hg (range 0-40 mm Hg). In patients with tetralogy, cardiac index four hours after operation averaged 2.8 L/M2/min. One patient with tetralogy and severe pulmonary hypertension died. Twelve patients with tetralogy were recatheterized 10 to 186 days after operation. The mean systolic pressure difference between right ventricle and pulmonary artery was 23 mm Hg. Residual obstructions were in the pulmonary valvular annulus. Cineangiograms did not show paradoxical motion of the right ventricular wall. Transatrial resection of right ventricular infundibular obstructions carries with it none of the consequences that often follow right ventriculotomy and this surgical approach satisfactorily relieves infundibular obstructions.