mmHg Drop Research Articles

Symptom Descriptors in Individuals Living With Undiagnosed Lower Extremity Peripheral Artery Disease.

Most individuals with lower extremity peripheral artery disease (PAD) experience symptoms other than claudication and live with undiagnosed PAD yet no tools exist to detect atypical PAD symptoms. The purpose of this study was to identify discriminating PAD symptom descriptors from a community-based sample of patients with no current diagnosis of PAD. Symptoms descriptors were obtained in a sample of 22 participants with persistent lower extremity symptoms pre/post exercise. An ankle brachial index with exercise was used to classify participants as "PAD" or "No PAD." Thirteen (59%) participants had a positive ankle brachial index (<0.9, ≥20% drop postexercise, or 30 mmHg drop postexercise). Symptoms do not disappear while walking, trouble keeping up with friends/family, positive response to pain or discomfort while sitting, and pain outside of the calves and thighs were associated with a positive ankle brachial index. Atypical symptoms were common among study participants. Symptoms while sitting and symptoms outside of the calf and thigh were negatively associated with a positive ankle brachial index. More precise descriptions of symptom characteristics are needed to improve PAD symptom recognition.

Treatment of Hypotension with Phenylephrine Increases Cerebral Microvascular Perfusion in a Rat Model of Acute Hemodilution

Intraoperative blood loss is associated with reduced mean arterial blood pressure (MAP), which may endanger vital organ perfusion, including the brain. Phenylephrine (PE), an α1-receptor agonist, is clinically utilized to treat intraoperative hypotension through vasoconstriction of resistance arterioles. Clinical studies suggest that raising MAP with PE may decrease perfusion to vital organs such as the brain. Experimental studies suggest that lower α-receptor density in the cerebral resistance arteries may lead to preserved brain perfusion after PE administration. We hypothesize that treatment of hypotension with PE will result in preserved brain perfusion due to different microvascular blood flow and tissue oxygen tension (pO2) responses in the brain and skeletal muscle in an experimental rat model. With Animal Care and Use Committee approval in accordance with ARRIVE-2 guidelines, spontaneously breathing anesthetized rats (1.5% isoflurane) underwent hemodilution by exchanging 40-50% estimated blood volume 1:1 with saline over 10 minutes to achieve a 10-20 mmHg drop in MAP. MAP (tail artery) was measured continuously. Hypotension was treated with PE (10-20 μg/kg/min iv) to increase MAP to a target above baseline MAP. Shed blood was re-infused after stopping the PE infusion. Microvascular blood flow (Oxyflo; Oxford Optronix, Oxford, UK, n=7) or microvascular pO2 (OxyLED, Oxyphor G4, Oxygen Enterprises Ltd., Philadelphia, PA, n=6) were measured continuously in the cerebral cortex (burr hole) and biceps femoris muscle simultaneously in each rat. Results were analyzed via one or two-way ANOVA, with significance achieved at p&lt;0.05. Baseline and post-hemodilution MAP values were comparable in both groups. PE infusion increased MAP to a mean level near 100 mmHg in both groups (p&lt;0.05). Microvascular blood flow and tissue pO2 were greater in the brain as compared to the muscle at all time points (p&lt;0.01 for both). PE infusion resulted in an increase in cerebral microvascular blood flow from baseline (1465±689 vs. 687±453 blood perfusion units (BPU); p&lt;0.001) that was sustained after discontinuing PE and during blood reinfusion. No changes in muscle microvascular flow were observed after PE infusion (294±129 vs. 168±113 BPU). A sustained increase in cerebral microvascular pO2 was measured following PE infusion (50.2±8.6 vs. 40.6±4.6 mmHg; p=0.02), whereas muscle tissue pO2 did not change (22.2±5.6 vs. 25.0±2.5 mmHg). A differential blood flow and microvascular pO2 response was observed following PE infusion in brain and skeletal muscle. Both cerebral microvascular blood flow and tissue pO2 demonstrated sustained increases after PE infusion. By contrast, no changes were observed in muscle microvascular blood flow and pO2. These results suggest that treatment of hypotension with PE administration preferentially increased cerebral vs. muscle perfusion in an experimental model of acute blood loss and fluid resuscitation. Canadian Anesthesiologists’ Society and University of Toronto Merit Award Support. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Abstract 15773: The Forgotten Ventricle: Insight Into Dynamic Effects of Left Ventricular Assist Device Ramp on Right Ventricle Function

Introduction: Left ventricular assist devices (LVAD) with magnetically levitated impellers have become standard due to hemocompatibility and survival profile. To optimize LVAD speeds, we previously introduced simultaneous right and left heart (RH/LH) catheterization during ramp studies. Here, we report pairing of this approach with pressure-volume (PV) assessment in a patient with a HeartMate 3 LVAD with mitral regurgitation (MR). The combined approach evaluated left ventricular (LV) hemodynamics and right ventricular (RV) PV-relationships during ramp testing. Methods: A 68-year-old male with ischemic cardiomyopathy, two years following HeartMate3 implantation, presented with NYHA class III symptoms. To evaluate for dyspnea, he underwent a RH/LH catheterization ramp study. RV PV-loops were created by use of a conductance catheter system, allowing creation of PV loops. Results: At the baseline LVAD speed of 5300 rotations per minute (RPM), right atrial pressure was elevated at 16 mmHg and pulmonary artery (PA) pressure of 26 mmHg. Left-end diastolic pressure (LVEDP) was elevated (16mmHg). Baseline cardiac index (CI) was 2.01 L/min/m 2 . Ramp testing was performed, increasing speeds from 5300 to 5800 RPM. Progressive LV unloading was observed with a 5 mmHg drop in LVEDP and a 3 mmHg drop in PA pressure. However, RV PV loop monitoring revealed a negative impact on RV contractility with the maximal elastance (Emax) slope demonstrating a 22% reduction. Furthermore, a 17% reduction in RV stroke volume was documented, while diastolic function remained unchanged. Thus, despite excellent LV offloading and diminishment of RV afterload, the significant negative impact on Emax resulted in no net increase in CI (+0.04 L/min/m 2 ) during the ramp evaluation. Inotrope therapy was initiated for RV function with increased LVAD RPM to outcompete MR. Conclusions: While RH/LH catheterization provides a real-time perspective of the interventricular relationship during ramp, the impact of increasing LVAD speeds on RV function has yet to be directly measured. Here, the RV PV loop relationship during LVAD ramp showed that although LVAD speed increases in the setting of MR may facilitate LV unloading, a drop in RV afterload did not compensate for reduction in RV contractility.

Abstract 14531: Higher Urban Health Index is Associated With Lower Ambulatory Blood Pressure in People Living in Southeast United States

Introduction: Hypertension is common in the Southeastern (SE) United States (US), which increases the risk of heart attack, stroke and other serious health problems. Ambulatory blood pressure (ABP) monitoring is the gold standard for diagnosing hypertension and provides better information on cardio- and cerebrovascular risk than office blood pressure (BP). However, the role of social determinants of health (SDOH) and their influence on BP elevation has been scarcely examined on a neighborhood level. The Urban Health Index (UHI), developed by the World Health Organization, has the potential to measure disparities in SDOH at the small areal level and examine inequalities in health outcomes. Hypothesis: Higher UHI is associated with lower blood pressure. Methods: We analyzed data using a longitudinal cohort established in 1989 with 724 individuals (age 5-16 in 1989, 50.8% females, 47.1% African Americans) from the Central Savannah River Area. A census tract level UHI was calculated using indicators of employment, income, and educational attainment. The UHI is a unitless and continuous measure (between 0 and 1). The relationship between UHI (2000 and 2010 data) and ABP was examined using a linear regression model, adjusted for age, sex, race, and family socioeconomic status. Results: Higher UHI was associated with lower ABP, with a 3.15 mmHg and 2.72 mmHg drop in 24-hour systolic and diastolic ABP with 1 unit increase in UHI, respectively (2000 data; p=0.010; p=0.020). The 2010 data showed similar trends, with an increase in UHI linked to a 2.66 mmHg decrease in mean 24-hour systolic ABP (P=0.042), with the diastolic ABP reduction (1.74 mmHg) in the same direction though not statistically significant (p=0.088). Conclusions: This is one of the first studies to delineate the correlation of ABP with UHI. Our results show that a higher UHI is associated with lower systolic and diastolic ABP, underscoring the influence of aggregate indicators of SDOH on individual health outcomes. Our results support the utility of the UHI as a tool to inform health policymakers on disparities on a sub-county level thereby informing targeted interventions to address these disparities.

Blood Pressure Changes During Mechanical Thrombectomy for Acute Ischemic Stroke Are Associated With Serious Early Treatment Complications: Symptomatic Intracerebral Hemorrhage and Malignant Brain Edema.

BackgroundSymptomatic intracranial hemorrhage (sICH) and malignant brain edema (MBE) are well-known deleterious endovascular treatment (EVT) complications that some studies found to be associated with postprocedural blood pressure (BP) variability. We aimed to evaluate their association with periprocedural BP changes, including its intraprocedural decrease.MethodsWe retrospectively analyzed the data of 132 consecutive patients that underwent EVT between 1 December 2018 and 31 December 2019, for anterior circulation ischemic stroke. Analyzed predictors of sICH and MBE included non-invasively obtained BP before and 5-min after treatment, intraprocedural relative decreases of BP from baseline, and its post-treatment increases. SICH was defined in accordance with the Safe Implementation of Thrombolysis in Stroke-Monitoring Study (SITS-MOST) criteria and MBE as brain edema with midline shift on the follow-up imaging. We used binary logistic regression analysis to investigate the association of BP parameters and the incidence of sICH and MBE.ResultsAmong the included patients, 11 (8.3%) developed sICH and 31 (23.5%) MBE. The intraprocedural decrease of mean arterial blood pressure (MAP) was independently associated with MBE occurrence (aOR per 10 mmHg drop from baseline 1.27; 95% CI 1.01–1.60; P = 0.040). Over 40% MAP drop was associated with a higher risk of sICH in the entire cohort (aOR 4.24; 95% CI 1.33–13.51; P = 0.015), but not in the subgroup with successful reperfusion (aOR 2.81; 95% CI 0.64–12.23; P = 0.169). Post-treatment systolic blood pressure (SBP) and MAP elevation above their minimal values during MT are significantly associated with the development of sICH (aOR per 10 mmHg SBP increase 1.78; 95% CI 1.15–2.76; P = 0.010 and aOR per 10 mmHg MAP increase 1.78; 95% CI 1.04–3.03; P = 0.035).ConclusionsIn the anterior circulation ischemic stroke patients relative MAP decrease during EVT is associated with a higher risk of MBE occurrence, and over 40% MAP drop with a higher incidence of both MBE and sICH. Post-treatment elevation of SBP and MAP increased the risk of sICH.

Peak Performance In Hypertrophic Cardiomyopathy

<h3>Background</h3> Progressive symptoms with exertion despite optimal medical therapy is common among patient with hypertrophic obstructive cardiomyopathy (HOCM). However, little is known about the exercise tolerance in this subset of patients. <h3>Case Description</h3> A 55 year old Caucasian male with long standing history of HOCM was referred for progressively worsening NYHA Class 3b symptoms. He denied any syncope or significant family history of sudden cardiac death. Baseline echocardiogram revealed normal LV systolic function with severe asymmetric septal hypertrophy to 21 mm, resting LVOT gradient of 27 mmHg, and severe pulmonary hypertension with right ventricular systolic pressure (RVSP) of 72 mmHg. He subsequently underwent stress echocardiography with resting LVOT gradient of 63 mmHg which markedly worsened with exertion to peak gradient of 218 mmHg. (Image 1A) He exercised for a total of 7 minutes and 37 seconds. The test was stopped due to dyspnea and 10 mmHg drop in blood pressure. Subsequent right and left heart catheterization which showed angiographically normal coronary arteries and normal cardiac outputs. The peak to peak gradient measured across the aortic valve was 79 mmHg. (Image 1B) After discussion with the heart team, the decision was made to pursue septal myectomy. Intraoperative transesophageal echocardiography prior to septal myectomy showed severe LVOT obstruction with mean gradient of 45 mmHg and peak gradient of 89 mmHg with associated moderate eccentric mitral regurgitation secondary to systolic anterior motion. Following myectomy, the LVOT gradient improved to a mean of 2 mmHg and peak of 5 mmHg. Patient was successfully discharged home within 4 days following surgery. <h3>Conclusion</h3> In patients with long standing HOCM, elevated gradients up to 218 mmHg may be well tolerated without syncope or ventricular arrythmias. Septal myectomy can provide dramatic improvement of LVOT gradient and long-lasting symptomatic relief.

Abstract P112: Orthostatic Hypotension, Orthostatic Hypertension And Ambulatory Blood Pressure In Patients With Chronic Kidney Disease: Findings From The Chronic Renal Insufficiency Cohort Study

Background: We recently demonstrated how orthostatic hypotension might be used to identify out-of-office blood pressure phenotypes, including white coat effects and nocturnal non-dipping patterns. However, these findings have not been replicated in a population with chronic kidney disease (CKD). Objective: To examine the association between orthostatic hypotension (OH) or hypertension (OHTN) with ambulatory BP in adults with CKD. Methods: CRIC is a prospective multicenter observation cohort study of participants with CKD. Standing BP at 1 minute and ABPM were obtained on 1467 participants. OH was defined as a 20mmHg drop in systolic BP (SBP) or 10 mmHg drop in diastolic BP (DBP) when changing from seated to standing positions. OHTN was defined as a 20 mmHg or 10mmHg rise in SBP or DBP respectively when changing from seated to standing position. White coat effects, based on ABPM, was defined as the difference between seated clinic and ambulatory BP. Systolic and diastolic night to day ratio was also calculated. Results: Of the 1467 participants (age: 58 ± 10 yrs, 44% female, 39% black) 73 had OH and 165 had OHTN). OH was positively associated with systolic and diastolic white coat effect (β=5.9 [0.9, 10.9] and 4.2 [1.3, 7.1]). OHTN was negatively associated with diastolic white coat effect (-4.9 [-6.9, -3]). OH was positively associated with systolic and diastolic night-to-day ratio (0.03 [0.01, 0.05] and 0.03 [0.01, 0.06] respectively). Conclusions: Clinic-based assessments of OH and OHTN may be useful for identifying BP phenotypes often missed with seated office BP measurements in CKD patients.

A Hemodynamic Study to assess response, tolerance and dose optimization of Carvedilol in Child Class A patients with Portal Hypertension

Background: Carvedilol has an established role in Chronic Liver disease (CLD) associated Portal Hypertension, however its role in specific subclasses of CLD has not been studied, neither the factors leading to non-response thereby predisposing such patients to variceal bleed with empiric therapy.&#x0D; Aims and Objectives: The purpose of this study was. 1. To evaluate the hemodynamic response to Carvedilol and optimum dosage in patients of CTP Class A Cirrhosis. 2. To determine any clinical variables that would help in differentiating responders from non-responders.&#x0D; Materials and Methods: In forty-three consecutive patients of chronic liver disease Child Turcotte Pugh (CTP) Class A with esophageal varices, Hepatic Venous Pressure Gradient (HVPG) was measured at baseline, 90 minutes after initial administration of 12.5 mg of Carvedilol and after 3 months of dose optimization.&#x0D; Results: Twenty-one (48.8%) patients demonstrated Acute Response and after dose optimization Chronic Response was seen in 29 (67.4%) patients with additional 8 (18.6%) patients responding to dose optimization. Fourteen (32.55%) patients failed to show any response. Low pre-drug Cardiac Output (CO), High pre-drug mean arterial pressure (MAP), more than 2.5mmHg drop in HVPG acutely, higher dose toleration of more than 18.5mg and lower change in HR predicted response.&#x0D; Conclusion: Patients with CTP Class A Cirrhosis with Portal Hypertension and Esophageal Varices tolerate Carvedilol well and nearly two-thirds show hemodynamic response when dose is optimized over a period of time, including patients who initially show no acute response. Nearly one-third of patients show no response even after dose optimization.

Risk factors for intradialytic decline in cerebral perfusion and impaired cerebral autoregulation in adults on hemodialysis.

Hemodialysis (HD) patients have significant burden of cerebral ischemic pathology noted on brain imaging. These ischemic type lesions maybe due to cerebral hypoperfusion that may be occurring during blood pressure (BP) fluctuations commonly noted during HD sessions. We evaluated changes in cerebral perfusion and measured an index of cerebral autoregulation (CA index) during HD to identify potential risk factors for intradialytic decline in cerebral perfusion and impaired cerebral autoregulation. In this cross-sectional study, we included HD patients age 50 years or older receiving conventional in-center HD. We measured cerebral perfusion during HD, using cerebral oximetry, and calculated the correlation between cerebral perfusion and BP during HD as an index of CA. We measured the association between potential risk factors for intradialytic decline in cerebral perfusion and CA index. We included 32 participants and 118 HD sessions in our analysis. The mean ± SD decline in cerebral oxygen saturation during HD was 6.5% ± 2.9% with a relative decline from baseline values of 9.2% ± 4.4%. Greater drop in systolic BP (SBP) during HD was associated with decline in cerebral oxygen saturation, p=0.02. Impaired CA index was noted in 37.3% of HD sessions. Having diabetes and >20 mmHg drop in SBP during HD were associated with increased (worse) CA index with an increase of 0.24 95%CI [0.06, 0.41] for diabetes and increase of 0.43 95%CI [0.27, 0.56] for a >20 mmHg drop in SBP during HD. Cerebral perfusion can decline during HD and is associated with changes in systemic BP. This may be due to impaired cerebral autoregulation in HD patients. Risk factors for worse CA index include diabetes and >20 mmHg drop in SBP during HD. This study highlights the risk of intradialytic decline in cerebral perfusion and impaired cerebral autoregulation in HD patients.

Internal Bleaching of a Non vital Anterior Tooth in Patient with Postural Hypotension

Postural hypotension is a form of low blood pressure, characterized a 20 mmHg decrease in systolic blood pressure or a 10 mmHg drop in diastolic blood pressure when rising from a sitting or lying position. This can cause syncope. A patient who comes to a dentist with postural hypotension may be a tough case. A 48-year-old woman arrived with postural hypotension and felt dissatisfied with the discolored and unsightly condition of her upper central incisor. This clinical case shows a management of postural hypotension patient in internal bleaching technique on non-vital teeth using 35% hydrogen peroxide. This therapy is simple, safety and adequate for patients who has postural hypotension with satisfactory results.

The Role of CO2 on Respiration and Metabolism During Hypercapnic and Normocapnic Recovery From Exercise

ABSTRACT High intensity exercise can lead to depletion of CO2 from the body (hypocapnia). This disturbance becomes more noticeable during recovery or between seasons of intermittent exercise, putting the subject in a neural fatigue state. Objectives: A possible hypothesis to address this condition would be to provide high CO2 mixtures (hypercapnic) during the recovery period from exercise in order to relieve hypocapnia. Methods: Eight men (23.8 ± 1.2 yrs, VO2max = 45 ± 1.9 ml▪kg-1▪min−1) performed cycling exercise at 80%VO2max for 6–7 min. During recovery (23 min) they inhaled hypercapnic air (EXP–21%O2, 3%CO2, and 76%N2) or normal air (CON–21%O2, 0.003%CO2, and 79%N2). Respiratory parameters were collected with open spirometry and heart rate was measured. Results: Exercise caused mild hypocapnia {9.9 mmHg drop of CO2 end-expiratory partial pressure (PETCO2)} in CON condition after exercise (p < .005). PETCO2 elevated close to the rest values during the three hypercapnic phases in EXP condition (main effect of condition p < .001 between EXP and CON), but after hypercapnic breathing it returned to hypocapnia similarly with CON. The ventilatory response (VE▪PETCO2 −1) and the exhaled volume of CO2 (VCO2) progressively increased during and also after ventilatory manipulations in EXP compared to CON condition (VE▪PETCO2 −1: post hoc p < .001, VCO2: pVCO2: p < .05-.001), and VO2 became lower after the end of second hypercapnic manipulation (p < .05 between EXP and CON). Conclusion: It seems that hypercapnic breathing after exercise is not a good strategy to reverse exercise hypocapnia, because of great hyperventilation caused by CO2 and exercise mechanisms during the recovery period leading to increased CO2 removal from body. This intervention may also decrease O2 supply and muscles blood flow.

Added Sugar Intake is Associated with Blood Pressure in Older Females.

Hypertension or high blood pressure (BP) is highly prevalent in the aging population. Notably, diet and lifestyle have a strong influence on BP. We investigated the association between dietary factors and BP in older adults. This cross-sectional study included 128 participants, aged 65–80 years. Multiple linear regressions were conducted to examine the associations between diet, including meats, vegetables, grains, fruits, dairy, fats, and added sugar, and BP. There was a significant association between intake of added sugar and systolic BP and diastolic BP in females after controlling for age, income, body mass index, physical activity levels, daily calorie intake, and BP medication use. The model predicted that a decrease of 2.3 teaspoons (0.5 standard deviation) of added sugar would result in a 8.4 mmHg drop in systolic BP and a 3.7 mmHg drop in diastolic BP. Whole fruit was associated with a reduction in diastolic BP in both males and females, and the model predicted that, for every 0.71 cup increase in whole fruit consumption, there would be a decrease in diastolic BP of 2.8 mmHg. Our findings support the dietary guidelines of limiting daily intake of added sugar and increasing fruit consumption to promote overall cardiovascular health in older adults.

Abstract 072: Paradoxical Blood Pressure Increase After Brief Patient Rest Period

Background: Office-based blood pressure (BP) measurement is subject to variations which may influence management. Objective: To assess the effect of rest period on repeat BP measurement. Methods: Clinic charts were review identified 200 encounters with BP re-measurement due to initial BP of &gt; 130/80 mmHg. BP was measured initially by a nurse, with the patient in a sitting position and the arm resting at the level of the heart. If BP was &gt; 130/80 mmHg, it was repeated by physician after resting the patient for 15 minutes. Mean age was 64 ± 12 years. Results: Among encounters with BP re-measurement, initial systolic BP (SBP) was 154 ± 25 mmHg, and diastolic BP 87 ± 15 mmHg. Upon re-measurement, 135 of 200 patients (68%) had lower SBP of 144 ± 21 mmHg compared with initial SBP of 161 ± 25 mmHg; a 17 mmHg drop (P &lt; 0.01). However, 53 of 200 patients (27%) had higher SBP of 149 ± 17 mmHg compared with initial SBP of 138 ± 14 mmHg; an 11 mmHg increase (P &lt; 0.01). Twelve patients (6%) had no BP change. In 47% (93/200) of encounters, BP re-measurement necessitated medication changes. Compared with the remaining patients, those with paradoxical increase in BP were younger (60 ± 9 years versus 66 ± 12 years; p &lt; 0.01), and with lower initial SBP (138 ± 14 versus 161 ± 25, p &lt; 0.01). Discussion: Hypertension is a major challenging public health problem. JNC 8 guidelines recommend that prior to BP measurement, patients should be seated quietly for at least 5 minutes in a chair, with feet on the floor, and arm supported at heart level; this may decrease initially elevated BP. However, 27% of our patients exhibited a paradoxical response, with elevation of the SBP after a 15 minute period of rest. The cause of this paradox is not clear, but may have resulted from white-coat hypertension during the rest period, which may be more common in younger patients, as noted in our study. This underscores the importance of ambulatory BP monitoring, especially in subsets of patients prone to having labile or white coat hypertension, to avoid the cost and side effects of BP overtreatment. Studying larger number of patients, and including patient with normal initial BP, may help clarify the mechanism and clinical significance of this observation.

Time-Dependent Drug Administration in Hypertension and its Effect on Blood Pressure Variability

Abstract Background: Optimizing blood pressure variability seems to represent a new therapeutic target in the management of hypertension. It is emphasized that scheduling at least one antihypertensive agent at bedtime, has the ability to reduce blood pressure. Aim of the study: We have proposed to test whether the divided treatment regimen also lowers blood pressure variability. Material and methods: A number of 37 treated hypertensive patients were enrolled, who underwent 24-hour ambulatory blood pressure monitoring (ABPM) at inclusion and at 8 weeks after therapeutic intervention with divided treatment regimen. BPV was assessed using average real variability. Results: The 24-hour systolic blood presure decreased from 139.5 ± 8.8 mmHg to 127.4 ± 8.9 mmHg (p &lt;0.0001), and we noted a 2.1 mmHg drop in blood pressure variability (p &lt;0.0001), as well as a two-fold increase in the percentage of dippers. After baseline ABPM assessment, in 15 cases an angiotensin-converting-enzyme-inhibitor was scheduled at bedtime, and in 10 cases it was given twice a day. In 17 cases a thiazide diuretic was administered in the afternoon, and in 18 cases a calcium channel blocker was administered at bedtime. Conclusions: For a more accurate management of patients with hypertension, the assessment of circadian blood pressure profile and the implementation of an individualized treatment that uses divided antihypertensive agents at bedtime or midday administration have the ability to optimize blood pressure control, restore dipper-profile, and decrease blood pressure variability.

Relationship between Hypotension and Cerebral Ischemia during Hemodialysis.

The relationship between BP and downstream ischemia during hemodialysis has not been characterized. We studied the dynamic relationship between BP, real-time symptoms, and cerebral oxygenation during hemodialysis, using continuous BP and cerebral oxygenation measurements prospectively gathered from 635 real-world hemodialysis sessions in 58 prevalent patients. We examined the relationship between BP and cerebral ischemia (relative drop in cerebral saturation >15%) and explored the lower limit of cerebral autoregulation at patient and population levels. Furthermore, we estimated intradialytic exposure to cerebral ischemia and hypotension for each patient, and entered these values into multivariate models predicting change in cognitive function. In all, 23.5% of hemodialysis sessions featured cerebral ischemia; 31.9% of these events were symptomatic. Episodes of hypotension were common, with mean arterial pressure falling by a median of 22 mmHg (interquartile range, 14.3-31.9 mmHg) and dropping below 60 mmHg in 24% of sessions. Every 10 mmHg drop from baseline in mean arterial pressure associated with a 3% increase in ischemic events (P<0.001), and the incidence of ischemic events rose rapidly below an absolute mean arterial pressure of 60 mmHg. Overall, however, BP poorly predicted downstream ischemia. The lower limit of cerebral autoregulation varied substantially (mean 74.1 mmHg, SD 17.6 mmHg). Intradialytic cerebral ischemia, but not hypotension, correlated with decreased executive cognitive function at 12 months (P=0.03). This pilot study demonstrates that intradialytic cerebral ischemia occurs frequently, is not easily predicted from BP, and may be clinically significant.

Impact of Bridging Income Generation with Group Integrated Care (BIGPIC) on Hypertension and Diabetes in Rural Western Kenya.

Rural settings in Sub-Saharan Africa (SSA) consistently report low participation in non-communicable disease (NCD) treatment programs and poor outcomes. The objective of this study is to assess the impact of the implementation of a patient-centered rural NCD care delivery model called Bridging Income Generation through grouP Integrated Care (BIGPIC). The study prospectively tracked participation and health outcomes for participants in a screening event and compared linkage frequencies to a historical comparison group. Rural Kenyan participants attending a voluntary NCD screening event were included within the BIGPIC model of care. The BIGPIC model utilizes a contextualized care delivery model designed to address the unique barriers faced in rural settings. This model emphasizes the following steps: (1) find patients in the community, (2) link to peer/microfinance groups, (3) integrate education, (4) treat in the community, (5) enhance economic sustainability and (6) generate demand for care through incentives. The primary outcome is the linkage frequency, which measures the percentage of patients who return for care after screening positive for either hypertension and/or diabetes. Secondary measures include retention frequencies defined as the percentage of patients remaining engaged in care throughout the 9-month follow-up period and changes in systolic (SBP) and diastolic blood pressure (DBP) and blood sugar over 12months. Of the 879 individuals who were screened, 14.2% were confirmed to have hypertension, while only 1.4% were confirmed to have diabetes. The implementation of a comprehensive microfinance-linked, community-based, group care model resulted in 72.4% of screen-positive participants returning for subsequent care, of which 70.3% remained in care through the 12months of the evaluation period. Patients remaining in care demonstrated a statistically significant mean decline of 21mmHg in SBP [95% CI (13.9 to 28.4), P < 0.01] and 5mmHg drop in DBP [95% CI (1.4 to 7.6), P < 0.01]. The implementation of a contextualized care delivery model built around the unique needs of rural SSA participants led to statistically significant improvements in linkage to care and blood pressure reduction.

OP.4C.04] SAFETY AND PERFORMANCE OF THE ENLIGHTN RENAL DENERVATION SYSTEM IN PATIENTS WITH DRUG-RESISTANT HYPERTENSION

Objective: Catheter-based renal denervation therapy is under evaluation in patients with resistant hypertension. To gain insights from a large dataset, we investigated safety and performance of the EnligHTN™ Renal Denervation System (St. Jude Medical) in patients with drug-resistant hypertension using pooled data from all trials performed to date. This is the first report of pooled data from the EnligHTN I-III trials through 24-months. Design and method: We analysed data from the EnligHTN trials with the following criteria: 18–80 years of age, office systolic BP >/=160 mmHg, >/=3 antihypertensive agents (including a diuretic), and renal artery diameter >/=4 mm, length >/=20 mm. All trials used the same renal artery ablation catheter. Results: 118 patients from these 3 studies (E1 n = 44, E2 n = 39, E3 n = 35), had 24-month follow up data available. Mean age was 61 yrs., mean office systolic BP (OSBP) at baseline of 177.1 mmHg and at 24 months of 151.3 mmHg. Therefore a 24-month reduction in OSBP of 25.8 mmHg was noted (p Results: 103 patients from these 3 studies (E1 n = 43, E2 n = 27, E3 n = 33) had ABPM data available at 24-months. Mean 24-hr systolic ABP at baseline was 152.1 mmHg and at 24-months was 140.5 mmHg. This 11.7 mmHg drop was statistically significant (p Results: 112 patients from these 3 studies (E1 n = 44, E2 n = 35, E3 n = 33) had eGFR data available at 24-months. Baseline was 79.8±19.9 mL/min/1.73 m2; 24-month was 77.1 ± 20.8 mL/min/1.73 m2. The change in eGFR at 24-months was not significant. Conclusions: Pooled data from the complete EnligHTN clinical trial dataset meeting traditional study definitions of resistant hypertension confirm the efficacy and safety of multi-electrode systems for renal artery denervation. Future randomised controlled trials in the patient population with next generation multi-electrode renal denervation systems are warranted. Serious Renal Artery Adverse Events occurred in less than 2% of the population. In addition changes in medication and predictors of blood pressure response will be presented.

Abstract P065: Pacemaker Tapping Maneuver in the Treatment of Orthostatic Hypotension

A 77 year old man was referred to us with fainting spells especially after standing/walking few steps. Initially he went to a neurologist and ENT specialist where the cause could not be determined and symptoms continued. During annual physical, he noticed that his blood pressue dropped when he stood up suddenly. He had severe fainting spells and was placed pacemaker in him.However,pacemaker did not make a huge difference.Blood Pressure monitoring was done and noticed 50 mmHg drop upon standing. Pacemaker was changed to constant pacing where his dizziness continued but he had no falls. He had periodic vision problems, numbness in fingers and legs, digestive problems, stomach issues and balance problems. His tilt table test showed orthostatic hypotension. Medical management (florinef, mestinone, midodrine) did not relieve his symptoms .Pacemaker sensor was turned on and made more sensitive that after he taps on the pacemaker, heart rate increases for 10 minutes. We told him to tap on pacemaker whenever he is dizzy and see if there is any improvement in orthostatic symptoms. The later treatment had made a huge difference; he is practically asymptomatic and was very much satisfied with his current health. He is using the tapping maneuver 4-5 times a day and his fainting disappeared and no syncope. First time our case report on Pacemaker tapping demonstrated significant improvement in treating symptoms of orthostatic hypotension.

The duration of the orthostatic blood pressure drop is predictive of death.

Orthostatic hypotension (OH) affects 6% of community-dwelling older people. This increases to 60% when non-invasive, continuous blood pressure (BP) monitoring is used, due to identification of transient drops in BP which recover rapidly. To determine the clinical relevance of these transient orthostatic BP drops. Five-year clinical observational study. One hundred three consecutive new patients attending a Falls and Syncope Clinic in the UK from 1 February 2009 underwent continuous BP monitoring during an active stand. BP profiles were analysed to quantify all reductions in BP, measuring the duration of any drop below diagnostic criteria. Five-year follow-up data were extracted from hospital clinical records to assess clinical outcomes. Systolic BP (sBP) dropped ≥20 mmHg in 76 (74%) individuals, with 65 (63%) having ≥10 mmHg drop in diastolic BP. However, only 22 (21%) cases were diagnosed clinically with OH. A sustained reduction in BP (≥30 s) had a sensitivity of 0.91 and specificity of 0.88 for a clinical diagnosis of OH, being more accurate than absolute BP reduction alone. A sustained reduction in sBP was associated with greater use of vasopressors (36%,P0.001) and an independent, significantly greater risk of death (45% at 5 years,P0.009). An orthostatic reduction in sBP lasting ≥30 s improves accuracy of diagnosis. Moreover, given the significant adverse outcomes with a sustained reduction, clinicians should consider this when diagnosing and treating patients, as transient OH does not appear to be clinically significant.

Abstract 411: Diurnal Variation of Blood Pressure in Medical Residents: MARINE 1 (Measures of Active Residents in Numerous Environments)

Residency training subjects healthy young people to frequent fluctuation in sleep-wake cycles. Although shift work is known to increase cardiovascular risk, little is known about the physiology of phase-shifted sleep in residency. This study uses 24-hr ambulatory blood pressure monitoring to investigate diurnal BP variation in medical residents working alternating day/night periods. We hypothesized that diurnal variation of BP is dependent upon sleep/wake status, not upon day/night hours. Residents were recruited from the Johns Hopkins Medicine Residency Program during the 2013-2014 academic year. Thirty-six individuals participated while working in three clinical environments (intensive care unit, general medicine wards, outpatient clinic), and during various sleep-wake schedules (night shift, 24-hr overnight call, day shift). BP was measured every 30 min during waking hours and every 2 hr during sleep. Residents self-reported during which hours they slept. Ninety-eight separate 24-hr periods of data were collected (Table 1). There is no difference in mean 24-hr SBP, awake SBP/DBP, or asleep SBP/DBP between those working different schedules. However, there are statistically significant differences in day SBP/DBP and night SBP/DBP between participants working different schedules. In all schedules, participants showed at least a 9 mmHg drop in SBP between awake and asleep . Diurnal variation of BP in this population is present, and dependent upon sleep/wake status, not day/night hours. Further investigation into the correlation between this reversal of diurnal BP variation and cardiovascular outcomes in shift workers is warranted.