Normal Resting Blood Pressure Research Articles

Prevalence and prognostic implications of hypertensive response to exercise in patients with hypertrophic cardiomyopathy

ObjectiveHypertensive response to exercise (HRE) is observed in patients with hypertrophic cardiomyopathy (HCM) with normal resting blood pressure (BP). However, the prevalence or prognostic implications of HRE in HCM remain unclear. MethodsIn this study, normotensive HCM subjects were enrolled. HRE was defined as systolic BP > 210 mmHg in men or >190 mmHg in women, or diastolic BP > 90 mmHg, or an increase in diastolic BP > 10 mmHg during treadmill exercise. All participants were followed for subsequent development of hypertension, atrial fibrillation (AF), heart failure (HF), sustained ventricular tachycardia/fibrillation (VT/VF), and all-cause death. Six hundred and eighty HCM patients were screened. Results347 patients had baseline hypertension, and 333 patients were baseline normotensive. 132 (40%) of the 333 patients had HRE. HRE was associated with female sex, lower body mass index and milder left ventricular outflow tract obstruction. Exercise duration and metabolic equivalents were similar between patients with or without HRE, but the HRE group had higher peak heart rate (HR), better chronotropic response and more rapid HR recovery. Conversely, non-HRE patients were more likely to exhibit chronotropic incompetence and hypotensive response to exercise. After a mean follow-up of 3.4 years, patients with and without HRE had similar risks of progression to hypertension, AF, HF, sustained VT/VF or death. ConclusionHRE is common in normotensive HCM patients during exercise. HRE did not carry higher risks of future hypertension or cardiovascular adverse outcomes. Conversely, the absence of HRE was associated with chronotropic incompetence and hypotensive response to exercise.

Caloric restriction overcomes pre-diabetes and hypertension induced by a high fat diet and renal artery stenosis.

Calorie restriction (CR) is a type of dietary intervention that is essential in weight loss through modulation of critical metabolic control pathways, is well established and understood in cases of systemic arterial hypertension, however, its role in renovascular hypertension is still unclear. Rats were divided into three groups: SHAM, and two groups that underwent surgery to clip the left renal artery and induce renovascular hypertension (OH and OHR). The SHAM diet was as follows: 14weeks normolipidic diet; OH: 2weeks normolipidic diet + 12weeks hyperlipidic diet, both ad libitum; OHR, 2weeks normolipidic diet + 8weeks ad libitum high-fat diet + 4weeks 40% calorie-restricted high-fat diet. Rats in the OHR group had decreased blood pressure, body weight, and glucose levels. Reductions in insulinemia and in lipid and islet fibrotic areas in the OHR group were observed, along with increased insulin sensitivity and normalization of insulin-degrading enzyme levels. The expression of nicotinamide phosphoribosyltransferase (NAMPT), insulin receptor (IR), sirtuin 1 (SIRT1), and complex II proteins were increased in the liver tissue of the OHR group. Strong correlations, whether positive or negative, were evaluated via Spearman's model between SIRT1, AMPK, NAMPT, PGC-1α, and NNMT expressions with the restoration of normal blood pressure, weight loss, glycemic and lipid panel, and mitochondrial adaptation. CR provided short-term beneficial effects to recover the physiological parameters induced by a high-fat diet and renal artery stenosis in obese and hypertensive animals. These benefits, even in the short term, can provide physiological benefits in the long term.

Indirect Blood Pressure Measurement in Horses: Is There an Influence of Age, Sex, Breed, Bodyweight, and Cardiac Diseases on Pressure Values?

Only few data regarding normal resting blood pressure in horses and the influence of cardiac diseases on arterial blood pressure are available in literature. The purpose of the present study was to investigate the possible influence of age, sex, breed, bodyweight, and cardiac diseases and their severity on blood pressure values measured in horses with cardiac disease and in a control group. For this case-control study, indirect blood pressure measurement was performed in 60 horses with different types of cardiac disease and in 23 healthy horses (control group), by means of an ultrasonic blood-flow technique. According to the echocardiographic findings, horses with cardiac abnormalities have been divided into two groups (with and without cardiac dimensional modifications). Multivariable linear regression analysis evaluated the influence of age, breed, sex, and cardiac diseases and their severity (regressors) on blood pressure. The results showed a significant influence of age on diastolic pressure in healthy horses. Furthermore, a significant influence of the presence of cardiac dilation in horses with cardiac disease on systolic and diastolic pressures was found. Single-regressor linear analysis showed that horses with cardiac dilation are significantly older than both horses without cardiac dimensional changes and those of control group. Further studies are necessary to better investigate the possible influence of the type of cardiac disease on blood pressure.

Prognostic Role of Hypertensive Response to Exercise in Patients With Repaired Coarctation of Aorta

BackgroundThis study aimed to determine the prevalence of hypertensive response to exercise (HRE) and its association with cardiovascular adverse events (CAEs) in patients with repaired coarctation of aorta (rCOA). MethodsWe retrospectively reviewed records of adult patients with rCOA who had cardiopulmonary exercise tests (CPETs) and follow-up from 1994 to 2014 at Mayo Clinic. Patients with residual COA, defined as aortic isthmus peak velocity >2.5 m/s, were excluded. HRE was defined as peak systolic blood pressure >200 mm Hg; CAEs were defined as cardiovascular death, stroke, acute coronary syndrome, heart failure hospitalization, and left ventricular ejection fraction (LVEF) < 35%. ResultsOne hundred thirty-eight patients (82 men [59%]) underwent 213 CPETs, with follow-up of 85 ± 13 months. Age at initial COA repair was 9 ± 3 years; age at initial CPET was 40 ± 13 years. HRE occurred in 26 (19%) patients, and 24 (92%) of the patients with HRE had normal resting blood pressure. There were no differences in age, blood pressure at rest, and CPET findings between patients with HRE and those with normotensive response to exercise. There were 28 CAEs in 24 patients (17%), and HRE was an independent risk factor for CAE (hazard ratio [HR], 1.46 [1.13–2.52]; P = 0.04). ConclusionsHRE can occur even in the setting of normal blood pressure at rest, and it is a risk factor for CAE. We speculate that patients with HRE represent a high-risk group of patients who, presumably, have occult, advanced vascular dysfunction. CPET can identify these patients. The benefit of intensive antihypertension therapy needs to be confirmed.

Homocysteine, visceral adiposity-related novel cardiometabolic risk factors, and exaggerated blood pressure response to the exercise treadmill test.

Exaggerated blood pressure response to exercise is a risk factor for the development of future hypertension. In this study, we aimed to investigate the association between homocysteine, epicardial fat thickness, nonalcoholic hepatic steatosis, and exaggerated blood pressure response to exercise. We included 44 normotensive and 40 patients with exaggerated blood pressure response to exercise who have normal resting blood pressure and without a previous diagnosis of hypertension. All patients underwent treadmill exercise test and clinical, ultrasonographic, and echocardiographic evaluation. Exaggerated blood pressure response to exercise is defined as peak exercise systolic blood pressure of at least 210 mmHg in men and at least 190 mmHg in women. Homocysteine and other biochemical parameters were determined with standardized automated laboratory tests. Mean age of all participants is 47.9±8.5 years, and 36 of 84 participants were female. The frequency of diabetes mellitus in both groups was similar (P=0.250). Homeostasis model assessment index-insulin resistance had a statistically insignificant trend to be higher in a patient with exercise hypertension (P=0.058). The nonalcoholic fatty liver was more frequent in patients with exercise hypertension (13.6 vs. 47.5%, P=0.002). Epicardial fat thickness was increased in patients with exercise hypertension (5.5±1.5 vs. 7.3±1.1 mm; P=0.001). However, homocysteine levels did not significantly differ between normotensive and exercise hypertensive patients [12.3 μmol/l (5.7-16.9 μmol/l) vs. 13 μmol/l (5.9-28.3 μmol/l); P=0.883]. In our study, homocysteine levels were not associated with exaggerated blood pressure response to exercise; however, fatty liver and epicardial fat thickness as visceral adiposity-related cardiometabolic risk factors were significantly related with exaggerated blood pressure response to exercise in patients without a previous diagnosis of hypertension.

Acute Esophageal Necrosis in a Patient with Liver Kidney Transplant

This is a case of a 63 year old African American male being evaluated for severe sepsis from healthcare associated pneumonia. He has history of liver cirrhosis from hepatitis C, end stage renal disease, combined liver and kidney transplantation in 2007 and was on immunosuppressant (mycophenolate mofetil, and cyclosporine), prednisone, and trimethoprim-sulfamethoxazole. He was admitted to the MICU and commenced on broad spectrum antibiotics. Cyclosporine was held due to AKI. On day 8, he developed diffuse abdominal pain, diarrhea consisting of dark stools, and one episode of coffee ground emesis. On physical exam, abdomen was non-distended with diffuse tenderness but no peritoneal signs. Labs revealed serum creatinine of 1.65 mg/dl. Patient exhibited mild leukocytosis to 13,300/uL. CT abdomen-pelvis revealed non-specific thickening of the esophagus. Naso-gastric tube returned non-bloody bilious gastric contents. Upper endoscopy revealed circumferential esophageal necrosis extending to mid esophagus. There was luminal narrowing in the distal esophagus. Biopsies taken were notable for “extensive necrotic debris with ulcerative acute esophagitis”. Patient was kept NPO, commenced on IV pantoprazole and sucralfate. Patient was treated with bowel rest, two weeks of antibiotics and four weeks of antifungals. Abdominal pain, loose stools and melena resolved. Repeat upper endoscopy one month later revealed complete resolution of esophageal necrosis. Acute esophageal necrosis(AEN) also known as ‘black esophagus’ is a rare disease with incidence of 0.01% to 0.2% in endoscopic studies. Mortality specific to AEN is 6% and is related to complications such as perforation. It presents with acute upper GI bleed in 90% of cases. Diagnosis is by endoscopic visualization of the characteristic esophageal features and this can be confirmed by pathology result of biopsy specimen but not required. Treatment consists of treating the underlying condition, restoration of normal blood pressure, acid suppression therapy with IV PPI, H2 blocker with or without sucralfate, bowel rest for a few days with total parenteral nutrition (TPN). Complete mucosal healing can be seen as early as 1 week. Complications include stenosis, superinfection and perforation. AEN is a rare disease entity that can be diagnosed only endoscopically and requires a high index of suspicion for early diagnosis and prompt treatment. Further research is needed to understand how to prevent it.Figure 1Figure 2Figure 3

OP.8A.01] EXERCISE-INDUCED HYPERTENSION AND CARDIAC HYPERTROPHY IN EPINEPHRINE-DEFICIENT MICE

Objective: Phenylethanolamine-N-methyltransferase (Pnmt) is required for the conversion of norepinephrine to epinephrine. Bao et al (2007) described that Pnmt-knockout (Pnmt-KO) mice have an increased ratio of left ventricular (LV) posterior wall thickness to internal dimensions (LVPW/LVID) but not overall cardiac hypertrophy. Pnmt-KO mice showed normal resting blood pressure (BP) but became hypertensive during treadmill exercise. The aim of this study was to evaluate cardiac morphological and functional alterations after chronic exercise in Pnmt-KO mice. Design and method: PCR-based genotyping was performed at the Pnmt locus of 10-week-old Pnmt-KO (Pnmt-/-) and WT mice (129x1/SvJ). Epinephrine and norepinephrine were quantified by RP-HPLC-ED in adrenal glands. Animals were submitted to a 6-week exercise training program. BP was measured by a photoelectric pulse detector. Mice were anesthetized (sevoflurane, 8%) and cardiac morphology and function were evaluated by echocardiography followed by morphometric analysis. Results: Epinephrine levels were vestigial in Pnmt-KO compared with WT mice. There were no differences in systolic and diastolic BP between untrained Pnmt-KO and WT mice. However, trained Pnmt-KO mice showed a significant increase in systolic BP when compared to trained WT mice. Our findings also showed that the ratios between heart weight (HW/BW) and LV weight (LVW/BW) and body weight (BW) were significantly increased in trained compared to untrained Pnmt-KO mice. Trained Pnmt-KO mice presented higher HW/BW than trained WT mice. Untrained Pnmt-KO mice display echocardiographic results similar to those reported by Bao et al (2007) while LVPW and IVS thicknesses, LV end-diastolic internal dimension (LVIDd) and LV mass indexed for body surface area (LVMi) were significantly increased in trained Pnmt-KO mice, indicating overall LV hypertrophic changes. Indexed LV end-diastolic volume (LVEDVi), indexed stroke volume (SVi) and cardiac index (CI) were significantly higher in trained Pnmt-KO than untrained Pnmt-KO mice. Conclusions: In conclusion, the increased BP in Pnmt-KO mice in response to exercise appears to be associated with an increase in LV wall thickness and chamber volume suggesting hypertrophic remodelling of the LV in Pnmt-KO mice. Epinephrine appears to be essential for maintaining normal BP, probably through β2-adrenoceptors-induced vessel relaxation, and preventing LV hypertrophy in chronic exercise.

Protective Effects of Vasodilatory Βeta-Blockers Carvedilol and Nebivolol against Glycerol Model of Rhabdomyolysis-Induced Acute Renal Failure in Rats.

BACKGROUND:Rhabdomyolysis (RM)-induced acute renal failure (ARF) accounts for about 10–40% of all cases of ARF.AIM:The present study investigated the possible protective effect of two nitric oxides (NO)-releasing third generation β-blockers, carvedilol (Carv) and nebivolol (Nebi), against RM-mimicking glycerol (Gly)-induced ARF in rats.MATERIAL AND METHODS:After 24 h dehydration, rats received a single dose of 50% Gly (8 ml/kg, im). They were treated with vehicle, Carv (2.5 mg/kg/day, po) or Nebi (10 mg/kg, po) for 3 successive days starting from an hour prior to Gly injection. Evaluation of blood pressure and locomotor activity was performed during the experiment. 72 h following Gly administration, total protein in the urine, serum levels of creatinine, blood urea nitrogen, sodium and potassium as well as the renal contents of malondialdehyde, reduced glutathione and NO were assessed, together with a histopathological examination of renal tissues.RESULTS:Carv and Nebi attenuated Gly-induced renal dysfunction and histopathological alterations. They decreased the Gly-induced oxidative stress and increased renal NO concentration. Restoration of normal blood pressure and improvement of locomotor activity were also observed.CONCLUSION:The results clearly demonstrate protective effects of Carv and Nebi against renal damage involved in RM-induced ARF and suggest a role of their antioxidant and NO-releasing properties.

Association between non-alcoholic hepatic steatosis and hyper reactive blood pressure response on the exercise treadmill test.

Non-alcoholic hepatic steatosis (HS) is associated with hypertension and increased cardiovascular risk. While Blood pressure hyper-reactive response (HRR) during peak exercise indicates an increased risk of incident hypertension and increased cardiovascular risk, no data on the association of non-alcoholic HS and HRR exists. In this study, we have evaluated the association of HS with HRR. We included 13 410 consecutive individuals with a mean age: 42.4 ± 8.9 years, 3561 (26.6%) female with normal resting blood pressure and without a previous diagnosis of hypertension, who underwent symptom limited exercise treadmill test, abdominal ultrasonography and clinical and laboratory evaluation. HS was detected by abdominal ultrasonography. HRR was defined by a peak exercise systolic blood pressure >220 mmHg and/or elevation of 15 mmHg or more in diastolic blood pressure from rest to peak exercise. The prevalence of HS was 29.5% (n = 3956). Overall, 4.6% (n = 619) of the study population presented a HRR. Subjects with HS had a higher prevalence of HRR (8.1 vs. 3.1%, odds ratio 2.8, 95% CI 2.4-3.3, P < 0.001). After adjustment for body mass index, waist circumference, fasting plasma glucose and low density lipoprotein cholesterol, HS (odds ratio 1.4, 95% CI 1.1-1.6, P = 0.002) remained independently associated with HRR. HS was additive to obesity markers in predicting exercise HRR. Non-alcoholic HS is independently associated with hyper-reactive exercise blood pressure response.

Awareness of Stress Related Blood Pressure in Society

Aim: The Aim Of This Survey Is To Create Awareness Of Stress Related In Society. Objective: This Survey Is Conducted Through A Standardised Questionnaire Distributed To Selective Number Of People To Create Awareness On Stress Related Pressure. Background: (Bp) Is The Exerted By Circulating Upon The Walls Of Vessels. In Other Words, Blood Pressure Usually Refers To The Arterial In The Systemic Circulation. It Is Usually Measured At A Person's Upper Arm. It Is One Of The Vital Signs Along With Respiratory Rate, Heart Rate, Body Temperature And Oxygen Saturation . Normal Resting In An Adult Is Approximately 120/80 Mm Hg. Some Behaviours Linked To Stress-Such As Overeating, Drinking Alcohol And Poor Sleeping Habits Can Cause High Pressure. Reason: This Survey Is Done In Order To Create Awareness Of Stress Related Among Society. If An Awareness Is Created, We Can Avoid The Risk Of Developing Long Term Stress Related Pressure. Result: The Survey Has Been Completed On Stress Related Among The Study Population.

Gene Expression in Experimental Aortic Coarctation and Repair: Candidate Genes for Therapeutic Intervention?

Coarctation of the aorta (CoA) is a constriction of the proximal descending thoracic aorta and is one of the most common congenital cardiovascular defects. Treatments for CoA improve life expectancy, but morbidity persists, particularly due to the development of chronic hypertension (HTN). Identifying the mechanisms of morbidity is difficult in humans due to confounding variables such as age at repair, follow-up duration, coarctation severity and concurrent anomalies. We previously developed an experimental model that replicates aortic pathology in humans with CoA without these confounding variables, and mimics correction at various times using dissolvable suture. Here we present the most comprehensive description of differentially expressed genes (DEGs) to date from the pathology of CoA, which were obtained using this model. Aortic samples (n=4/group) from the ascending aorta that experiences elevated blood pressure (BP) from induction of CoA, and restoration of normal BP after its correction, were analyzed by gene expression microarray, and enriched genes were converted to human orthologues. 51 DEGs with >6 fold-change (FC) were used to determine enriched Gene Ontology terms, altered pathways, and association with National Library of Medicine Medical Subject Headers (MeSH) IDs for HTN, cardiovascular disease (CVD) and CoA. The results generated 18 pathways, 4 of which (cell cycle, immune system, hemostasis and metabolism) were shared with MeSH ID’s for HTN and CVD, and individual genes were associated with the CoA MeSH ID. A thorough literature search further uncovered association with contractile, cytoskeletal and regulatory proteins related to excitation-contraction coupling and metabolism that may explain the structural and functional changes observed in our experimental model, and ultimately help to unravel the mechanisms responsible for persistent morbidity after treatment for CoA.

Hemorrhagic‐Shock/Resuscitation‐Induced Microvascular Permeability in the Rat Mesentery is Exacerbated by Acute Alcohol Intoxication

Traumatic injury and acute alcohol intoxication (AAI) often are associated, yet little is known about how this combination affects the microcirculation. We tested the hypothesis that AAI exacerbates hemorrhagic shock and resuscitation (HS-R)-induced microvascular leakage. Carotid artery, jugular vein, and indwelling gastric catheters were placed in anesthetized Sprague Dawley rats. Following 2-3 days recovery, conscious, unrestrained rats received 2.5 g/kg alcohol i.g., followed by HS-R (fixed pressure of 40 mm Hg for 1 h, followed by Lactated Ringers (LR), 40% i.v. bolus + 2x total blood removed (TBR) infusion over 1 h). Following HS-R, the rats were anesthetized for intravital microscopy of the mesenteric microcirculation. FITC-Albumin served as a tracer to determine extravasation, quantified by measuring integrated optical intensity (IOI) of the extravascular areas adjacent to postcapillary venules. Alcohol antagonizes the restoration of normal blood pressure during fluid resuscitation. Alcohol increases extravasation of FITC-Albumin compared to sham-water rats (209.5 ± 42 sham-alcohol vs. 62.3 ± 9 sham-water, p<0.001). HS-R also increases hyperpermeability compared to respective shams (698.4 ± 311 HS-R-water vs. 62.3 ± 9 sham-water, p<0.01; and 1061.7 ± 208 HS-R-alcohol vs. 209.5 ± 42 sham-alcohol, p<0.001). HS-R-induced hyperpermeability was significantly higher in alcohol animals compared to water (1061.7 ± 208 HS-R-alcohol vs 698.4 ± 311 HS-R-water, p<0.05). These data show that AAI worsens trauma-induced microvascular hypermeability. Supported by NIH grants R01HL098215 and R21AA020049, and the ABMRF/Foundation for Alcohol Research.

Cardiovascular control during exercise in type 2 diabetes mellitus.

Controlled studies of male and female subjects with type 2 diabetes mellitus (DM) of short duration (~3–5 years) show that DM reduces peak (L·min−1 and mL·kg−1·min−1) by an average of 12–15% and induces a greater slowing of the dynamic response of pulmonary during submaximal exercise. These effects occur in individuals less than 60 years of age but are reduced or absent in older males and are consistently associated with significant increases in the exercise pressor response despite normal resting blood pressure. This exaggerated pressor response, evidence of exertional hypertension in DM, is manifest during moderate submaximal exercise and coincides with a more constrained vasodilation in contracting muscles. Maximum vasodilation during contractions involving single muscle groups is reduced by DM, and the dynamic response of vasodilation during submaximal contractions is slowed. Such vascular constraint most likely contributes to exertional hypertension, impairs dynamic and peak responses, and reduces exercise tolerance. There is a need to establish the effect of DM on dynamic aspects of vascular control in skeletal muscle during whole-body exercise and to clarify contributions of altered cardiovascular control and increased arterial stiffness to exertional hypertension.

Left ventricular diastolic function and cardiometabolic factors in obese normotensive children

Background and aimLeft ventricular (LV) hypertrophy and diastolic function have been found to be associated with obesity and hypertension in adults. However, there are scarce data about the association of obesity itself to cardiac alteration in children. The aim of this study was to detect early changes in LV structure and function in obese children and whether they are associated with the biomarkers of metabolic risk and endothelial activation. Methods and resultsA total of 130 children aged 7–16 years (88 obese and 42 normal-weight children) were studied. All children had normal resting blood pressure. Two-dimensional ultrasound with M-mode imaging was performed to assess the LV mass index (LVMi), calculated as LV mass/height2.7, and the peak diastolic of pulmonary venous flow velocity (PVFD). Tissue Doppler imaging was used to analyze ventricular performance through the ratio of the transmitral peak early filling velocity to the early average diastolic peak myocardial velocity (E/E′). The indicators of metabolic control, inflammation, and endothelial cell activation were evaluated. Compared to the controls, the obese subjects had significantly higher LVMi and E/E′ and lower PVFD values, the two latest being found especially in severely obese subjects. In the multivariate analysis, the parameters of diastolic function (E/E′ and PVFD) were independently associated with obesity, apolipoprotein A1, soluble vascular cell endothelial molecule-1 (sVCAM-1), and retinol-binding protein 4 (RBP4). ConclusionAn echocardiographic evaluation of diastolic function is a useful tool to detect early cardiac changes in obese children. Emergent cardiovascular risk markers such as apolipoprotein A1, RBP4, and sVCAM-1 are associated with the parameters of diastolic function.

Predictors of exaggerated exercise-induced systolic blood pressures in young patients after coarctation repair

In normotensive subjects, an exaggerated blood pressure response to exercise is associated with the development of resting hypertension. We sought to determine the prevalence of elevated blood pressures during exercise in post-operative coarctation patients with normal resting blood pressure, and investigate associations with exercise-induced hypertension in this population. A total of 38 patients were enrolled after end-to-end anastomosis repair and resting normotension. All patients underwent anthropometric and blood pressure measurements, echocardiographic evaluation of function, arterial stiffness assessment by pulse wave velocity, and a graded exercise test. An abnormal response was defined as a maximum systolic blood pressure greater than the 95th percentile of published normal values. Correlation analyses and stepwise regression analyses were performed. The mean age was 12.7 years, including 79% male patients. The mean resting systolic blood pressure was 111.3 millimetres of mercury and the mean exercise systolic blood pressure was 178.1 millimetres of mercury. The prevalence of a systolic blood pressure greater than the 95th percentile was 16.7%. In multivariate analysis, the exercise systolic blood pressure index was associated with body mass index, age, aortic valve annulus, shortening fraction, and pulse wave velocity (R2 equal to 0.79, p equal to 0.0009). Estimates of ventricular filling and indexed left ventricular mass were elevated. There is a risk of elevated systolic blood pressure during exercise in normotensive patients after coarctation repair. Resting blood pressures are useful but not sufficient. Echocardiography demonstrated abnormalities suggestive of a chronic cardiac burden despite resting normotension. Regular imaging may be necessary to improve long-term outcomes. New paradigms for the continued follow-up of these patients are necessary.

Atrial Fibrillation Complicating Left Pneumothorax After Malpositioning of a Double-Lumen Tube

A 66-year-old woman (weight 133.3 lbs, height 158 cm) was scheduled for atrial septal defect (ASD) repair through a thoracotomy. Preoperative chest radiography was normal, and an electrocardiogram showed an incomplete right bundle-branch block. Transesophageal echocardiography revealed moderate right atrium and ventricle dilation, a pulmonary arterial pressure of 52 mmHg, and an ASD-associated left-to-right shunt. In the operating room, her blood pressure was 125/75 mmHg, her heart rate was 94 beats/min, and the SpO2 was 97% on room air. The patient was intubated with a 35F left-sided double-lumen tube (DLT) under direct laryngoscopy to a depth of 31 cm at the incisors. The DLT placement was checked by auscultation. During manual ventilation, increased airway resistance was noted, and no breath sounds were heard over either lung fields. The tube was pulled back 2 cm, and bilateral breath sounds were again documented. The end-tidal carbon dioxide waveform was present on the monitor. At that time, rapid-rate atrial fibrillation of 130 beats/min occurred with a blood pressure of 63/40 mmHg. Phenylephrine boluses were given to maintain hemodynamic stability. Correct positioning of the DLT was confirmed by fiberoptic bronchoscopy. Meanwhile, SpO2 remained within the normal range. Soon thereafter, a median sternotomy was performed instead of a thoracotomy, and a left pneumothorax was diagnosed and released by pleural opening. This was followed by rapid conversion of the atrial fibrillation into sinus rhythm and restoration of normal blood pressure. During one-lung ventilation, barotrauma from excessive tidal volume and high airway pressure may occur if a left-sided DLT is positioned distally such that the entire tidal volume is directed to only one lobe.1Silvalingam P. Tio R. Tension pneumothorax, pneumomediastinum, pneumoperitoneum, and subcutaneous emphysema in a 15-year-old Chinese girl after a double-lumen tube intubation and one-lung ventilation.J Cardiothorac Vasc Anesth. 1999; 13: 312-315Abstract Full Text PDF PubMed Scopus (34) Google Scholar, 2Malik S. Shapiro W.A. Jablons D. et al.Contralateral tension pneumothorax during one-lung ventilation for lobectomy: Diagnosis aided by fiberoptic bronchoscopy.Anesth Analg. 2002; 95: 570-572PubMed Google Scholar In our patient, high peak airway pressure may have been generated during manual ventilation to check the DLT position, which was placed too distal. The average depth of insertion for patients 170 cm tall was 29 cm, and for each 10-cm increase or decrease in height, the average placement depth was increased or decreased 1 cm.3Brodsky J.B. Benumof J.L. Ehrenwerth J. et al.Depth of placement of left double-lumen endobronchial tubes.Anesth Analg. 1991; 73: 570-572Crossref PubMed Scopus (95) Google Scholar A pneumothorax presents as increased airway pressure, decreased tidal volume, decreased SpO, and hypotension. Sudden-onset atrial fibrillation may occur for a variety of reasons during anesthesia. Our patient developed rapid-rate atrial fibrillation with hypotension, probably as a complication of the pneumothorax, which was diagnosed only after sternotomy. Had we initiated one-lung ventilation, cardiovascular collapse would have developed. Previous reports showed that a pneumothorax may be associated with numerous electrocardiographic changes.4Price J.W. Novel electrocardiographic changes associated with iatrogenic pneumothorax.Am J Crit Care. 2006; 15: 415-419PubMed Google Scholar, 5Strizik B. Forman R. New ECG changes associated with a tension pneumothorax.Chest. 1999; 115: 1742-1744Crossref PubMed Scopus (37) Google Scholar The sudden rise in intrathoracic pressure and rotation around the longitudinal axis of the heart has been suggested as a cause of these changes. A proposed mechanism for PR-segment changes is atrial ischemia caused by compression of air on the collapsed lung and subsequently on the heart. In our patient, a shift in heart position secondary to the pneumothorax in addition to the atrial enlargement may have predisposed to this mechanical irritation and subsequent atrial fibrillation. In conclusion, we report a case of atrial fibrillation complicating a left pneumothorax that was caused by barotrauma after malpositioning of a DLT in the presence of an ASD. Atrial fibrillation was reverted by releasing the pneumothorax. The diagnosis of a pneumothorax should be considered during DLT insertion whenever a patient develops cardiovascular instability.

Predictive value of breath-holding pressure response as a new diagnostic test for latent arterial hypertension detection

Background. Latent arterial hypertension (LAH) is a serious health problem and is often underdiagnosed in routine examination. Thus, a sensitive and economical test to detect latent hypertension is needed. Objective. To assess the opportunity of pressure response to voluntary breath holding (30 second breath holding test) to detect masked arterial hypertension in young subjects. Design and methods. 269 young subjects (18-36 years old) with no clinical signs of cardiovascular disease, diabetes mellitus, any chronic diseases including pulmonary diseases, who did not do sports professionally, underwent 30 second breath holding test. Results. The results of breath holding and 24 hour monitoring tests coincided in 250 out of 269 cases (93 %). Latent hypertensions was diagnosed (by 24 hour blood pressure monitoring) in none of the subjects with normal or high normal resting blood pressure and negative breath holding test (negative predictive value - 100 %). For subjects with normal or high normal resting blood pressure, a positive breath holding test (53 subjects) detected latent arterial hypertension in 34 subjects (positive predictive value - 64 %). Conclusions. The breath holding test helps to effectively exclude latent arterial hypertension in healthy subjects and accurately identifies subjects who should be further tested for arterial hypertension.

Cardiac tamponade following pericarditis 18 days after catheter ablation of atrial fibrillation

Sirs: One year ago, a 68-year-old man was treated with pulmonary vein (PV) isolation for paroxysmal AF. Ostial PV isolation was performed by using the High Density Mesh Ablator Catheter (Bard Electrophysiology, Lowell, MA, USA). The deployed Mesh Ablator was positioned at the anatomical PV ostium. Lesions were created with pulsed RF energy from an RF energy generator (Stockert 1000 XP, Biosense Webster Inc., Diamond Bar, CA, USA). Target temperature was set at 58 C with a maximum energy output of 80 W. After each energy delivery time of 300 s, endocardial electrograms from 10 mm distal to the anatomical PV ostium were obtained with the Mesh Ablator Catheter to confirm circumferential PV isolation. With an energy delivery time of 600 s for each PV, isolation of all PVs could be achieved. Due to AF recurrence, re-ablation was performed 12 months after the first procedure. Before re-ablation, electrical reconnection was documented with a decapolar spiral catheter (Reflexion Spiral Variable Radius Catheter, St. Jude Medical, St. Paul, MN, USA). No PV stenosis was found. For re-ablation, we used a threedimensional mapping system (Ensite NavX, Verismo, St. Jude Medical) for navigation based on a fusion with cardiac computer tomography, and an irrigated-tip ablation catheter (Cool Path, St. Jude Medical) for ablation. To achieve better catheter stability, a steerable sheath (Agilis, St. Jude Medical) was used. The ablation setting consisted of a preselected catheter tip temperature of 42 C, a power of 30 W, and a flow rate of 17 mL/min. Adjacent to the oesophagus visualized with contrast medium swallowed immediately before sedation of the patient, the power was reduced to 25 W. The right sided and the left sided PVs were isolated with a single circumferential antral line and additional ablations at the carina between the superior and inferior PVs, respectively (Fig. 1). After completion of the ablation lines, successful PV isolation was confirmed with the spiral catheter for all PVs. The cumulative RF delivery time was 2,860 s, the procedure time was 230 min. The procedure was completed without any complications. The patient was discharged on a betablocker, an ACE-inhibitor, a proton pump inhibitor and phenprocoumon. The patient was readmitted to hospital 14 days after the second AF ablation because of symptoms suggestive of pericarditis. The leading symptoms consisted of fever up to 38.5 C and chest pain, exacerbated by movement and inspiration. The 12-lead ECG showed non-ischemic STelevation in leads I, II, III, aVL, aVF and V2–V6 (Fig. 2) and blood work showed elevated c-reactive protein and erythrocyte sedimentation rate. A CT scan of the chest and echocardiography revealed no abnormalities. Cardiac enzymes remained negative and the patient was therefore treated with anti-inflammatory drugs. On the fourth day of hospitalization, the patient experienced syncope with subsequent severe cardiogenic shock accompanied by dilated jugular veins associated with not detectable blood pressure. Transthoracic echocardiography performed in the ICU showed significant pericardial effusion. At pericardiocentesis, 400 ml of blood could be removed resulting in restoration of normal blood pressure. Laboratory analyses of the removed blood showed a haemoglobin level comparable to peripheral blood with an oxygen saturation of 91% indicating active bleeding from the left atrium. At this point of time, INR was 1.93 and the T. Lambert (&) C. Steinwender F. Leisch R. Hofmann Cardiovascular Division, City Hospital Linz, Krankenhausstrase 9, 4020 Linz, Austria e-mail: Thomas.lambert@akh.linz.at

Manifestation of renal disease in obesity: pathophysiology of obesity-related dysfunction of the kidney.

Albuminuria in individuals whose body mass index exceeds 40 kg/m(2) is associated with the presence of large glomeruli, thickened basement membrane and epithelial cellular (podocyte) distortion. Obstructive sleep apnea magnifies glomerular injury as well, probably through a vasoconstrictive mechanism. Insulin resistance from excess fatty acids is exacerbated by decreased secretion of high molecular weight adiponectin from adipose cells in the obese state. Adiponectin potentiates insulin in its post-receptor signaling resulting in glucose oxidation in mitochondria. Recent studies of podocyte physiology have concentrated on the structural and functional requirements that prevent glomerular albumin leakage. The architecture of the podocyte involves nephrin and podocin, proteins that cooperate to keep slit pores between foot processes competent to retain albumin. Insulin and adiponectin are necessary for high-energy phosphate generation. When fatty acids bind to albumin, the toxicity to proximal renal tubules is magnified. Albumin and fatty acids are elevated in urine of individuals with obesity related nephrotic syndrome. Fatty acid accumulation and resistin inhibit insulin and adiponectin. Study of cytokines produced by adipose tissue (adiponectin and leptin) and macrophages (resistin) has led to a better understanding of the relationship between weight and hypertension. Leptin, is presumably secreted after food intake to inhibit the midbrain/hypothalamic appetite centers. Resistance to leptin results in excess signaling to hypothalamic sympathetics leading to hypertension. Demonstration of the existence of a cerebral receptor mutation provide evidence for a role in hypertension of a central nervous reflex arc in humans. Further understanding of obesity-related renal dysfunction has been accomplished recently using experimental models. Rapid weight loss following bariatric surgery may reverse renal pathology of obesity with restoration of normal blood pressure.

Epinephrine Regulation of Hemodynamics in Catecholamine Knockouts and the Pithed Mouse

Phenylethanolamine N-methyltransferase (PNMT) catalyzes synthesis of epinephrine (E) and is present in the brain, heart, and adrenal. E is a neurotransmitter and important hormone; however, its role in regulating cardiovascular dynamics is still unclear. We generated an E-deficient mouse model by knocking out the PNMT gene. The PNMT KO mouse had normal resting blood pressure, while treadmill exercise caused hypertension, suggesting an impaired response to stress in the absence of the stress hormone E. As PNMT occurs at a lower concentration in many extra-adrenal tissues including the brain, we set up a pithed mouse model to study the peripheral effects of E on cardiovascular dynamics, using pithing to eliminate central and reflex effects. The pithed mouse requires different surgical techniques and stimulation voltages than rats, and showed voltage- and frequency-dependent blood pressure responses to electrical stimuli. Stimulation with the alpha-adrenergic agonist phenylephrine gave a marked systolic pressor response, while the beta2 agonist salbutamol lowered diastolic blood pressure. The pithed PNMT KO mouse had an exaggerated blood pressure response to salbutamol, suggesting beta2 receptor supersensitivity. A targeted KO of tyrosine hydroxylase in PNMT-producing cells produced a mouse deficient in catecholamines in the adrenal. These targeted KO mice displayed significantly smaller pressor responses than pithed control mice. We find that E release during stress prevents an excessive increase in blood pressure.