Use of a Minimally Invasive Uncalibrated Cardiac Output Monitor in Patients Undergoing Cesarean Section under Spinal Anesthesia: Report of Four Cases

Bliacheriene F, Carmona MJC, Barretti CFM, Haddad CMF, Mouchalwat ES, Bortlotto MRFL, Francisco RPV, Zugaib M - Use of a Minimally Invasive Uncalibrated Cardiac Output Monitor in Patients Undergoing Cesarean Section under Spinal Anesthesia: Report of Four Cases. Background and Objectives: Hemodynamic changes are observed during cesarean section under spinal anesthesia. Non-invasive blood pressure (BP) and heart rate (HR) measurements are performed to diagnose these changes, but they are delayed and inaccurate. Other monitors such as filling pressure and cardiac output (CO) catheters with external calibration are very invasive or inaccurate. The objective of the present study was to report the cardiac output measurements obtained with a minimally invasive uncalibrated monitor (LiDCO rapid) in patients undergoing cesarean section under spinal anesthesia. Case report: After approval by the Ethics Commission, four patients agreed to participate in this study. They underwent cesarean section under spinal anesthesia while at the same time being connected to the LiDCO rapid by a radial artery line. Cardiac output, HR, and BP were recorded at baseline, after spinal anesthesia, after fetal and placental extraction, and after the infusion of oxytocin and metaraminol. We observed a fall in BP with an increase of HR and CO after spinal anesthesia and oxytocin infusion; and an increase in BP with a fall in HR and CO after bolus of the vasopressor. Conclusions: Although this monitor had not been calibrated, it showed a tendency for consistent hemodynamic data in obstetric patients and it may be used as a therapeutic guide or experimental tool.

Adult-onset Still`s Disease with Pulmonary and Cardiac Involvement and Response to Intravenous Immunoglobulin

Cardiopulmonary manifestations of adult-onset Still`s disease (AOSD) include pericarditis, pleural effusion, transient pulmonary infiltrates, pulmonary interstitial disease and myocarditis. Serositis are common but pneumonitis and myocarditis are not and bring elevated risk of mortality. They may manifest on disease onset or flares. Previously reported cases were treated with high-dose glucocorticoids and immunosupressants and, when refractory, intravenous immunoglobulin (IVIG). We report an AOSD patient whose flare presented with severe pleupneumonitis and myopericarditis and, following nonresponse to a methylprednisolone pulse, high dose of prednisone and cyclosporine A, recovered after a 2-day 1g/kg/day IVIG infusion.

Risk factors for sudden unexpected cardiac death in Tasmanian men

Background: Sudden unexpected cardiac death (SUCD) accounts for approximately 25% of deaths from ischaemic heart disease (IHD) but is relatively poorly understood because of the difficulties involved in researching aetiology. Clinical differences between instances of SUCD and those cases of acute chest pain that survive long enough to be proven as myocardial infarction but are eventually fatal might reflect differences in aetiology. Aims: To determine the risk factors for sudden unexpected cardiac death in Tasmanian men. Methods: A population-based case-control method was used with the study population, an estimated 125,225 men aged 25-74 years living in the island State of Tasmania, Australia. The case group of 102 men who had a SUCD was validated using necropsy reports, hospital records and information provided by the usual general practitioner. Cases were matched with 204 community controls. Spouses or partners of eligible subjects answered a detailed questionnaire. Multi-variate odds ratios (ORs) for risk factors were calculated using stepwise analysis. Results: Risk factors measured included: smoking habit, treated hypertension, hypercholesterolaemia, diabetes mellitus, family history of LHD, alcohol intake and exercise habits. Independent risk factors for SUCD were: history of diabetes mellitus (OR=4.2, 95% CI: 1.39, 12.81), current smoking status (OR=3.5, 95% CI: 1.80, 6.82), and family history of IHD (OR=2.6, 95% CI: 1.34, 4.92). Conclusions: Some accepted risk factors for acute myocardial infarction (AMI) also predict sudden death in men with no history of coronary disease. Efforts to reduce smoking, the incidence of diabetes mellitus and mean blood pressure must be continued as SUCD is, by definition, untreatable but is potentially avoidable in many instances.

Gastric Bypass and Cardiac Autonomic Activity: Influence of Gender and Age

Obesity is associated with increased sympathetic activity and higher mortality. Treatment of this condition is often frustrating. Roux-en-Y gastric bypass is the most effective technique nowadays for treatment of obesity. The aim of the present study is to assess the effects of this surgery on the cardiac autonomic activity, including the influence of gender and age, through heart rate variability (HRV) analysis. The study group consisted of 71 obese patients undergoing gastric bypass. Time domain measures of HRV, obtained from 24-h Holter recordings, were evaluated before and 6 months after surgery, and the results were compared. Percentage of interval differences of successive normal sinus beats greater than 50 ms (pNN50) and square root of the mean squared differences of successive normal sinus beat intervals (rMSSD) was used to estimate the short-term components of HRV, related to the parasympathetic activity. Standard deviation of intervals between all normal sinus beats (SDNN) was related to overall HRV. SDNN, pNN50, and rMSSD showed significant increase 6 months after surgery (p < 0.001, p = 0.001 and p = 0.002, respectively). Men presented a greater increase of SDNN than women (p = 0.006) during the follow-up. There was a difference in rMSSD evolution for age groups (p = 0.002). Only younger patients presented significant increase of rMSSD. Overall HRV increased 6 months after surgery; this increase was more evident in men. Cardiac parasympathetic activity increased also, but in younger patients only.

Modulation of human cardiac function through 4 beta-adrenoceptor populations

In human heart there is now evidence for the involvement of four beta-adrenoceptor populations, three identical to the recombinant beta(1)-, beta(2)- and beta(3)-adrenoceptors, and a fourth as yet uncloned putative beta-adrenoceptor population, which we designate provisionally as the cardiac putative beta(4)-adrenoceptor. This review described novel features of beta-adrenoceptors as modulators of cardiac systolic and diastolic function. We also discuss evidence for modulation by unoccupied beta(1)- and beta(2)-adrenoceptors. Human cardiac and recombinant beta(1)- and beta(2)-adrenoceptors are both mainly coupled to adenylyl cyclase through Gs protein, the latter more tightly than the former. Activation of both human beta(1)- and beta(2)-adrenoceptors not only increases cardiac force during systole but also hastens relaxation through cyclic AMP-dependent phosphorylation of phospholamban and troponin I, thereby facilitating diastolic function. Furthermore, both beta(1) and beta(2)-adrenoceptors can mediate experimental arrhythmias in human cardiac preparations elicited by noradrenaline and adrenaline. Human ventricular beta(3)-adrenoceptors appear to be coupled to a pertussis toxin-sensitive protein (Gi?). beta(3)-Adrenoceptor-selective agonists shorten the action potential and cause cardiodepression, suggesting direct coupling of a Gi protein to a K+ channel. In a variety of species, including man, cardiac putative beta(4)-adrenoceptors mediate cardiostimulant effects of non-conventional partial agonists, i.e. high affinity beta(1)- and beta(2)-adrenoceptor blockers that cause agonist effects at concentrations considerably higher than those that block these receptors. Putative beta(4)-adrenoceptors appear to be coupled positively to a cyclic AMP-dependent cascade and can undergo some desensitisation.

Can Tricuspid Annuloplasty of the Donor Heart Reduce Valve Insufficiency following Cardiac Transplantation with Bicaval Anastomosis?

Background: The aim of this study was to evaluate the degree of tricuspid valve insufficiency after orthotopic cardiac transplantation with bicaval anastomosis and prophylactic donor heart annuloplasty. Methods: At present, our cardiac transplantation experience includes 478 cases. After January 2002, we included 30 consecutive patients in this study who had undergone orthotopic cardiac transplantation and survived >6 months. The patients were divided into 2 groups: group I, 15 patients who underwent transplantation with prophylactic tricuspid annuloplasty on the donor heart with the De Vega technique; and group II, 15 patients who underwent transplantation without this procedure. Their preoperative clinical characteristics were the same. During the late postoperative follow-up, the degree of tricuspid insufficiency was evaluated by transthoracic Doppler echocardiography and assessed according to the Simpson scale: 0, absent; 1, mild; 2, moderate; and 3, severe. Hemodynamic parameters were evaluated invasively by means of a Swan-Ganz catheter during routine endomyocardial biopsies. Results: The mean follow-up time was 26.9 +/- 5.4 months (range, 12-36 months). In group I, 1 patient (6.6%) died from infection in the 18th month after the operation; the death was not related to the annuloplasty. In group II, 1 death (6.6%) occurred after 10 months because of rejection (P > .05). After the 24-month follow-up, the mean degree of tricuspid insufficiency was 0.4 +/- 0.5 in group I and 1.7 +/- 0.9 in group II (P < .05). Similarly, the 2 groups were significantly different with respect to the right atrium pressure, which was higher in group II. Conclusions: Prophylactic tricuspid annuloplasty on the donor heart was able to reduce significantly the degree of valvular insufficiency, even in cardiac transplantation with bicaval anastomosis; however, it did not modify significantly the hemodynamic performance of the allograft during the investigation period. It is very important to extend the observation period and casuistics to verify other benefits that this technique may offer.

Validation of a strategy to diagnose coronary artery disease and predict cardiac events in high-risk renal transplant candidates

Background We validated a strategy for diagnosis of coronary artery disease ( CAD) and prediction of cardiac events in high-risk renal transplant candidates ( at least one of the following: age >= 50 years, diabetes, cardiovascular disease). Methods A diagnosis and risk assessment strategy was used in 228 renal transplant candidates to validate an algorithm. Patients underwent dipyridamole myocardial stress testing and coronary angiography and were followed up until death, renal transplantation, or cardiac events. Results The prevalence of CAD was 47%. Stress testing did not detect significant CAD in 1/3 of patients. The sensitivity, specificity, and positive and negative predictive values of the stress test for detecting CAD were 70, 74, 69, and 71%, respectively. CAD, defined by angiography, was associated with increased probability of cardiac events [log-rank: 0.001; hazard ratio: 1.90, 95% confidence interval (CI): 1.29-2.92]. Diabetes (P=0.03; hazard ratio: 1.58, 95% CI: 1.06-2.45) and angiographically defined CAD (P=0.03; hazard ratio: 1.69, 95% CI: 1.08-2.78) were the independent predictors of events. Conclusion The results validate our observations in a smaller number of high-risk transplant candidates and indicate that stress testing is not appropriate for the diagnosis of CAD or prediction of cardiac events in this group of patients. Coronary angiography was correlated with events but, because less than 50% of patients had significant disease, it seems premature to recommend the test to all high-risk renal transplant candidates. The results suggest that angiography is necessary in many high-risk renal transplant candidates and that better noninvasive methods are still lacking to identify with precision patients who will benefit from invasive procedures. Coron Artery Dis 21: 164-167 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

Challenges in Using Stem Cells for Cardiac Repair

Of the many diseases discussed in the context of stem cell therapy, those concerning the heart account for almost one-third of the publications in the field. However, the long-term clinical outcomes have been disappointing, in part because of preclinical studies failing to optimize the timing, number, type, and method of cell delivery and to account for shape changes that the heart undergoes during failure. In situations in which cardiomyocytes have been used in cell therapy, their alignment and integration with host tissue have not been realized. Here we review the present status of direct delivery of stem cells or their derivative cardiomyocytes to the heart and the particular challenges each cell type brings, and consider where we should go from here.

A Randomized Trial of a Skin Sealant to Reduce the Risk of Incision Contamination in Cardiac Surgery

Background. Immobilizing skin microbes is a rational approach to reducing contamination of surgical sites by endogenous microorganisms. Methods. This randomized, controlled, parallel-group, multicenter, open-label clinical trial (ClinicalTrials.gov NCT00467857) enrolled 300 adults scheduled for elective coronary artery bypass graft surgery. Patients received iodine-based skin preparations followed by a cyanoacrylate-based skin sealant or skin preparations alone. Microbiological samples collected from sternal and graft incision sites immediately before any skin preparation, at the wound border after skin incision, and at the incision after fascial closure were evaluated quantitatively. Results. In evaluable patients, mean microbial counts in collected samples increased at the sternal site after fascial closure compared with after skin incision by 0.37 log(10) colony-forming units (CFU)/mL in the skin sealant group (n = 120) and by 0.57 log10 CFU/mL in the control group (n = 132) (p = 0.047, Wilcoxon rank sum test). At the graft site, mean microbial counts increased by 0.09 (n = 119) and 0.27 (n = 127) log(10) CFU/mL, respectively (p = 0.037). There was a 35.3% relative risk reduction in surgical site infection (SSI) occurring in the skin sealant group (9 of 146 patients, 6.2%) versus the control group (14 of 147 patients, 9.5%). In obese patients (body mass index [BMI] > 30.0 to <= 37.0 kg/m(2)), the relative risk reduction for SSI associated with skin sealant was 83.3%. Conclusions. Pretreatment with skin sealant protects against contamination of the surgical incision by migration of skin microbes. Further data are needed to confirm the impact of this technology on SSI rates in clinical practice. (Ann Thorac Surg 2011;92:632-7) (C) 2011 by The Society of Thoracic Surgeons ADULT CARDIAC

Intramyocardial transplantation of fibroblasts expressing vascular endothelial growth factor attenuates cardiac dysfunction

In this study, we analyzed whether transplantation of cardiac fibroblasts (CFs) expressing vascular endothelial growth factor (VEGF) mitigates cardiac dysfunction after myocardial infarction (MI) in rats. First, we observed that the transgene expression lasts longer (45 vs 7 days) when fibroblasts are used as vectors compared with myoblasts. In a preventive protocol, induction of cardiac neovascularization accompanied by reduction in myocardial scar area was observed when cell transplantation was performed 1 week before ischemia/reperfusion and the animals analyzed 3 weeks later. Finally, the therapeutic efficacy of this approach was tested injecting cells in a fibrin biopolymer, to increase cardiac retention, 24 h post-MI. After 4 weeks, an increase in neovascularization and a decrease in myocardial collagen were observed only in rats that received cells expressing VEGF. Basal indirect or direct hemodynamic measurements showed no differences among the groups whereas under pharmacological stress, only the group that received cells expressing VEGF showed a significant reduction in end-diastolic pressure and improvement in stroke volume and cardiac work. These results indicate that transplantation of CFs expressing VEGF using fibrin biopolymer induces neovascularization and attenuates left ventricle fibrosis and cardiac dysfunction in ischemic heart. Gene Therapy (2010) 17, 305-314; doi:10.1038/gt.2009.146; published online 10 December 2009

The Bypass Angioplasty Revascularization Investigation 2 Diabetes Randomized Trial of Different Treatment Strategies in Type 2 Diabetes Mellitus With Stable Ischemic Heart Disease Impact of Treatment Strategy on Cardiac Mortality and Myocardial Infarction

Background-The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial in 2368 patients with stable ischemic heart disease assigned before randomization to percutaneous coronary intervention or coronary artery bypass grafting strata reported similar 5-year all-cause mortality rates with insulin sensitization versus insulin provision therapy and with a strategy of prompt initial coronary revascularization and intensive medical therapy or intensive medical therapy alone with revascularization reserved for clinical indication(s). In this report, we examine the predefined secondary end points of cardiac death and myocardial infarction (MI). Methods and Results-Outcome data were analyzed by intention to treat; the Kaplan-Meier method was used to assess 5-year event rates. Nominal P values are presented. During an average 5.3-year follow-up, there were 316 deaths (43% were attributed to cardiac causes) and 279 first MI events. Five-year cardiac mortality did not differ between revascularization plus intensive medical therapy (5.9%) and intensive medical therapy alone groups (5.7%; P = 0.38) or between insulin sensitization (5.7%) and insulin provision therapy (6%; P = 0.76). In the coronary artery bypass grafting stratum (n = 763), MI events were significantly less frequent in revascularization plus intensive medical therapy versus intensive medical therapy alone groups (10.0% versus 17.6%; P = 0.003), and the composite end points of all-cause death or MI (21.1% versus 29.2%; P = 0.010) and cardiac death or MI (P = 0.03) were also less frequent. Reduction in MI (P = 0.001) and cardiac death/MI (P = 0.002) was significant only in the insulin sensitization group. Conclusions-In many patients with type 2 diabetes mellitus and stable ischemic coronary disease in whom angina symptoms are controlled, similar to those enrolled in the percutaneous coronary intervention stratum, intensive medical therapy alone should be the first-line strategy. In patients with more extensive coronary disease, similar to those enrolled in the coronary artery bypass grafting stratum, prompt coronary artery bypass grafting, in the absence of contraindications, intensive medical therapy, and an insulin sensitization strategy appears to be a preferred therapeutic strategy to reduce the incidence of MI. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00006305. (Circulation. 2009;120:2529-2540.)

Pressure-Frequency Sensing Subxiphoid Access System for Use in Percutaneous Cardiac Electrophysiology: Prototype Design and Pilot Study Results

We have designed, built, and tested an early prototype of a novel subxiphoid access system intended to facilitate epicardial electrophysiology, but with possible applications elsewhere in the body. The present version of the system consists of a commercially available insertion needle, a miniature pressure sensor and interconnect tubing, read-out electronics to monitor the pressures measured during the access procedure, and a host computer with user-interface software. The nominal resolution of the system is <0.1 mmHg, and it has deviations from linearity of <1%. During a pilot series of human clinical studies with this system, as well as in an auxiliary study done with an independent method, we observed that the pericardial space contained pressure-frequency components related to both the heart rate and respiratory rate, while the thorax contained components related only to the respiratory rate, a previously unobserved finding that could facilitate access to the pericardial space. We present and discuss the design principles, details of construction, and performance characteristics of this system.

AT(1) receptor participates in the cardiac hypertrophy induced by resistance training in rats

Resistance training is accompanied by cardiac hypertrophy, but the role of the renin-angiotensin system (RAS) in this response is elusive. We evaluated this question in 36 male Wistar rats divided into six groups: control (n = 6); trained (n = 6); control + losartan (10 mg.kg(-1).day(-1), n = 6); trained + losartan (n = 6); control + high-salt diet (1%, n = 6); and trained + high-salt diet (1%, n = 6). High salt was used to inhibit the systemic RAS and losartan to block the AT(1) receptor. The exercise protocol consisted of: 4 x 12 bouts, 5x/wk during 8 wk, with 65-75% of one repetition maximum. Left ventricle weight-to-body weight ratio increased only in trained and trained + high-salt diet groups (8.5% and 10.6%, P < 0.05) compared with control. Also, none of the pathological cardiac hypertrophy markers, atrial natriuretic peptide, and alpha MHC (alpha-myosin heavy chain)-to-beta MHC ratio, were changed. ACE activity was analyzed by fluorometric assay (systemic and cardiac) and plasma renin activity (PRA) by RIA and remained unchanged upon resistance training, whereas PRA decreased significantly with the high-salt diet. Interestingly, using Western blot analysis and RT-PRC, no changes were observed in cardiac AT(2) receptor levels, whereas the AT(1) receptor gene (56%, P < 0.05) and protein (31%, P < 0.05) expressions were upregulated in the trained group. Also, cardiac ANG II concentration evaluated by ELISA remained unchanged (23.27 +/- 2.4 vs. 22.01 +/- 0.8 pg/mg, P > 0.05). Administration of a subhypotensive dose of losartan prevented left ventricle hypertrophy in response to the resistance training. Altogether, we provide evidence that resistance training-induced cardiac hypertrophy is accompanied by induction of AT(1) receptor expression with no changes in cardiac ANG II, which suggests a local activation of the RAS consistent with the hypertrophic response.

Left ventricular Systolic function and outcome after in-hospital cardiac arrest

Background - The effect of prearrest left ventricular ejection fraction ( LVEF) on outcome after cardiac arrest is unknown. Methods and Results - During a 26-month period, Utstein-style data were prospectively collected on 800 consecutive inpatient adult index cardiac arrests in an observational, single-center study at a tertiary cardiac care hospital. Prearrest echocardiograms were performed on 613 patients ( 77%) at 11 +/- 14 days before the cardiac arrest. Outcomes among patients with normal or nearly normal prearrest LVEF ( >= 45%) were compared with those of patients with moderate or severe dysfunction ( LVEF < 45%) by chi(2) and logistic regression analyses. Survival to discharge was 19% in patients with normal or nearly normal LVEF compared with 8% in those with moderate or severe dysfunction ( adjusted odds ratio, 4.8; 95% confidence interval, 2.3 to 9.9; P < 0.001) but did not differ with regard to sustained return of spontaneous circulation ( 59% versus 56%; P = 0.468) or 24-hour survival ( 39% versus 36%; P = 0.550). Postarrest echocardiograms were performed on 84 patients within 72 hours after the index cardiac arrest; the LVEF decreased 25% in those with normal or nearly normal prearrest LVEF ( 60 +/- 9% to 45 +/- 14%; P < 0.001) and decreased 26% in those with moderate or severe dysfunction ( 31 +/- 7% to 23 +/- 6%, P < 0.001). For all patients, prearrest beta-blocker treatment was associated with higher survival to discharge ( 33% versus 8%; adjusted odds ratio, 3.9; 95% confidence interval, 1.8 to 8.2; P < 0.001). Conclusions - Moderate and severe prearrest left ventricular systolic dysfunction was associated with substantially lower rates of survival to hospital discharge compared with normal or nearly normal function.

Ligaments of the Posterior and Lateral Talar Processes: MRI and MR Arthrography of the Ankle and Posterior Subtalar Joint with Anatomic and Histologic Correlation

OBJECTIVE. MRI and combined ankle and posterior subtalar MR arthrography in cadavers were used to evaluate the ligaments of the posterior and lateral talar processes. Subsequent anatomic and histologic correlation was performed. MATERIALS AND METHODS. Ten cadaveric ankles were used. Routine radiography and MRI were initially performed. Ankle and posterior subtalar MR arthrography, followed by anatomic and histologic analysis, was then performed to allow better assessment of the ligaments of the lateral and posterior talar process. RESULTS. In all subjects, MR arthrography provided superior delineation of the articular and periarticular structures, as well as the ligaments. The lateral talocalcaneal and medial talocalcaneal ligaments were best seen in the axial and coronal planes, respectively. The axial plane was best for visualizing the fibulotalocalcaneal ligament, and the sagittal plane was best for evaluating the posterior talocalcaneal ligament. The anterior and posterior talofibular ligaments and the posterior tibiotalar ligament (superficial and deep portions) were best seen in the axial plane. Histologic analysis was correlated to anatomic sectioning and showed the attachment sites of these ligaments. CONCLUSION. Combined ankle and posterior subtalar MR arthrography enhances visualization of the ligaments attaching to the posterior and lateral talar processes, including the posterior, lateral, and medial talocalcaneal and fibulotalocalcaneal ligaments.