Changes in plasma free fatty acid levels in septic patients are associated with cardiac damage and reduction in heart rate variability

Free fatty acids (FFAs) have been shown to produce alteration of heart rate variability (HRV) in healthy and diabetic individuals. Changes in HRV have been described in septic patients and in those with hyperglycemia and elevated plasma FFA levels. We studied if sepsis-induced heart damage and HRV alteration are associated with plasma FFA levels in patients. Thirty-one patients with sepsis were included. The patients were divided into two groups: survivors(n = 12) and nonsurvivors (n = 19). The following associations were investigated: (a) troponin I elevation and HRV reduction and (b) clinical evolution and HRV index, plasma troponin, and plasma FFA levels. Initial measurements of C-reactive protein and gravity Acute Physiology and Chronic Health Evaluation scores were similar in both groups. Overall, an increase in plasma troponin level was related to increased mortality risk. From the first day of study, the nonsurvivor group presented a reduced left ventricular stroke work systolic index and a reduced low frequency (LF) that is one of HRV indexes. The correlation coefficient for LF values and troponin was r(2) = 0.75 (P < 0.05). All patients presented elevated plasma FFA levels on the first day of the study (5.11 +/- 0.53 mg/mL), and this elevation was even greater in the nonsurvivor group compared with the survivors (6.88 +/- 0.13 vs. 3.85 +/- 0.48 mg/mL, respectively; P < 0.05). Cardiac damage was confirmed by measurement of plasma troponin I and histological analysis. Heart dysfunction was determined by left ventricular stroke work systolic index and HRV index in nonsurvivor patients. A relationship was found between plasma FFA levels, LFnu index, troponin levels, and histological changes. Plasma FFA levels emerged as possible cause of heart damage in sepsis.

Clinical usefulness of B-type natriuretic peptide in the diagnosis of pleural effusions due to heart failure

Background and objective: Light`s criteria are frequently used to evaluate the exudative or transudative nature of pleural effusions. However, misclassification resulting from the use of Light`s criteria has been reported, especially in the setting of diuretic use in patients with heart failure (HF). The objective of this study was to evaluate the utility of B-type natriuretic peptide (BNP) measurements as a diagnostic tool for determining the cardiac aetiology of pleural effusions. Methods: Patients with pleural effusions attributable to HF (n = 34), hepatic hydrothorax (n = 10), pleural effusions due to cancer (n = 21) and pleural effusions due to tuberculosis (n = 12) were studied. Diagnostic thoracentesis was performed for all 77 patients. Receiver operating characteristic (ROC) curves were constructed to determine the diagnostic accuracy of plasma BNP and pleural fluid BNP for the prediction of HF. Results: The areas under the ROC curves were 0.987 (95% CI 0.93-0.998) for plasma BNP and 0.949 (95% CI 0.874-0.986) for pleural fluid BNP, for distinguishing between patients with pleural effusions caused by HF (n = 34) and those with pleural effusions attributable to other causes (n = 43). The cut-off concentrations with the highest diagnostic accuracy for the diagnosis of HF as the cause of pleural effusion were 132 pg/mL for plasma BNP (sensitivity 97.1%, specificity 97.4%) and 127 pg/mL for pleural fluid BNP (sensitivity 97.1%, specificity 87.8%). Conclusions: In patients with pleural effusions of suspected cardiac origin, measurements of BNP in plasma and pleural fluid may be useful for the diagnosis of HF as the underlying cause.

Implications of prevalent and incident diabetes mellitus on left ventricular geometry and function in the ageing heart: The MONICA/KORA Augsburg cohort study

Background and Aim: It is unclear to what extent diabetes modulates the ageing-related adaptations of cardiac geometry and function. Methods and Results: We examined 1005 adults, aged 25-74 years, from a population-based survey at baseline in 1994/5 and at follow-up in 2004/5. We compared persistently non-diabetic individuals (ND; no diabetes at baseline and at follow-up, n = 833) with incident (ID; non-diabetic at baseline and diabetic at follow-up, n = 36) and with prevalent diabetics (PD; diabetes at baseline and follow-up examination, n = 21). Left ventricular (LV) geometry and function were evaluated by echocardiography. Statistical analyses were performed with multivariate linear regression models. Over ten years the PD group displayed a significantly stronger relative increase of LV mass (+9.34% vs. +23.7%) that was mediated by a more pronounced increase of LV end-diastolic diameter (+0% vs. +6.95%) compared to the ND group. In parallel, LA diameter increased (+4.50% vs. +12.7%), whereas ejection fraction decreased (+3.02% vs. -4.92%) more significantly in the PD group. Moreover, at the follow-up examination the PD and ID groups showed a significantly worse diastolic function, indicated by a higher E/EM ratio compared with the ND group (11.6 and 11.8 vs. 9.79, respectively). Conclusions: Long-standing diabetes was associated with an acceleration of age-related changes of left ventricular geometry accumulating in an eccentric remodelling of the left ventricle. Likewise, echocardiographic measures of systolic and diastolic ventricular function deteriorated more rapidly in individuals with diabetes. (C) 2009 Elsevier B.V. All rights reserved.

Heart-lung interactions with different ventilatory settings during acute lung injury and hypovolaemia: an experimental study

Background. The functional haemodynamic variables pulse pressure variation (PPV), stroke volume variation (SVV), and systolic pressure variation (SPV) are widely used to assess haemodynamic status. However, it is not known how these perform during acute lung injury (ALI). This study evaluated the effects of different ventilatory strategies on haemodynamic parameters in pigs with ALI during normovolaemia and hypovolaemia. Methods. Eight anaesthetized Agroceres pigs [40 (1.9) kg] were instrumented with pulmonary artery, PiCCO, and arterial catheters and ventilated. Three ventilatory settings were randomly assigned for 10 min each: tidal volume (VT) 15 ml kg(-1) and PEEP 5 cm H(2)O, VT 8 ml kg(-1) and PEEP 13 cm H(2)O, or VT 6 ml kg(-1) and PEEP 13 cm H(2)O. Data were collected at each setting at baseline, after ALI (lung lavage+Tween 1.5%), and ALI with hypovolaemia (haemorrhage to 30% of estimated blood volume). Results. At baseline, high VT increased PPV, SVV, and SPV (P < 0.05 for all). During ALI, high VT significantly increased PPV and SVV [(P = 0.002 and P = 0.008) respectively.]. After ALI with hypovolaemia, ventilation at VT 6 ml kg(-1) and PEEP 13 cm H(2)O decreased the accuracy of functional haemodynamic variables to predict hypovolaemia, with the exception of PPV (area under the curve 0.875). The parameters obtained by PiCCO were less influenced by ventilatory changes. Conclusions. VT is the ventilatory parameter which influences functional haemodynamics the most. During ventilation with low VT and high PEEP, most functional variables are less able to accurately predict hypovolaemia secondary to haemorrhage, with the exception of PPV.

Effects of Sleep Apnea on Nocturnal Free Fatty Acids in Subjects with Heart Failure

Study Objectives: Sleep apnea is common in patients with congestive heart failure, and may contribute to the progression of underlying heart diseae. Cardiovascular and metabolic complications of sleep apnea have been attributed to intermittent hypoxia. Elevated free fatty acids (FFA) are also associated with the progression of metabolic, vascular, and cardiac dysfunction. The objective of this study was to determine the effect of intermittent hypoxia on FFA levels during sleep in patients with heart failure. Design and interventions: During sleep, frequent blood samples were examined for FFA in patients with stable heart (ejection fraction < 40%). In patients with severe sleep apnea (apnea-hypopnea index = 15.4 +/- 3.7 events/h; average low SpO(2) = 93.6%). In patients with severe sleep apnea, supplemental oxygen at 2-4 liters/min was administered on a subsequent night to eliminate hypoxemia. Measurements and Results: Prior to sleep onset, controls and patients with severe apnea exhibited a similar FFA level. After sleep onset, patients with severe sleep apnea exhibited a marked and rapid increase in FFA relative to control subjects. This increase persisted throughout NREM and REM sleep exceeding serum FFA levels in control subjects by 0.134 mmol/L (P = 0.0038) Supplemental oxygen normalized the FFA profile without affecting sleep architecture or respiratory arousal frequency. Conclusion: In patients with heart failure, severe sleep apnea causes surges in nocturnal FFA that may contribute to the accelerated progression of underlying heart disease. Supplemental oxygen prevents that FFA elevation.

Influence of Parasympathetic Modulation in Doppler Mitral Inflow Velocity in Individuals without Heart Disease

Background: The relation between left ventricular filing velocities determined by Doppler echocardiography and autonomic nervous system function assessed by heart rate variability (HRV) is unclear. The aim of this study was to evaluate the influence of the autonomic nervous system assessed by the time and frequency domain indices of HRV in the Doppler indices of left ventricular diastolic filling velocities in patients without heart disease. Methods: We studied 451 healthy individuals (255 female [56.4%]) with normal blood pressure, electrocardiogram, chest x-ray, and treadmill electrocardiographic exercise stress test results, with a mean age of 43 +/- 12 (range 15-82) years, who underwent transthoracic Doppler echocardiography and 24-hour electrocardiographic ambulatory monitoring. We studied indices of HRV on time (standard deviation [SD] of all normal sinus RR intervals during 24 hours, SD of averaged normal sinus RR intervals for all 5-minute segments, mean of the SD of all normal sinus RR intervals for all 5-minute segments, root-mean-square of the successive normal sinus RR interval difference, and percentage of successive normal sinus RR intervals > 50 ms) and frequency (low frequency, high frequency, very low frequency, low frequency/high frequency ratio) domains relative to peak flow velocity during rapid passive filling phase (E), atrial contraction (A), E/A ratio, E-wave deceleration time, and isovolumic relaxation time. Statistical analysis was performed with Pearson correlation and logistic regression. Results: Peak flow velocity during rapid passive filling phase (E) and atrial contraction (A), E/A ratio, and deceleration time of early mitral inflow did not demonstrate a significant correlation with indices of HRV in time and frequency domain. We found that the E/A ratio was < 1 in 45 individuals (10%). Individuals with an E/A ratio < 1 had lower indices of HRV in frequency domain (except low frequency/high frequency) and lower indices of the mean of the SD of all normal sinus RR intervals for all 5-minute segments, root-mean-square of the successive normal sinus RR interval difference, and percentage of successive normal sinus RR intervals > 50 ms in time domain. Logistic regression demonstrated that an E/A ratio < 1 was associated with lower HF. Conclusion: Individuals with no evidence of heart disease and an E/A ratio < 1 demonstrated a significant decrease in indexes of HRV associated with parasympathetic modulation. (J Am Soc Echocardiogr 2010;23: 762-5.)

Intrapericardial Ranolazine Prolongs Atrial Refractory Period and Markedly Reduces Atrial Fibrillation Inducibility in the Intact Porcine Heart

Introduction: Extensive experimental studies and clinical evidence (Metabolic Efficiency with Ranzolazine for Less Ischemia in Non-ST-Elevation Acute Coronary Syndrome Thrombolysis in Myocardial Infarction-36 [MERLIN TIMI-36] trial) indicate potential antiarrhythmic efficacy of the antianginal agent ranolazine. Delivery of agents into the pericardial space allows high local concentrations to be maintained in close proximity to myocardial tissue while systemic effects are minimized. Methods and Results: The effects of intrapericardial (IPC) administration of ranolazine (50-mg bolus) on right atrial and right ventricular effective refractory periods (ERP), atrial fibrillation threshold, and ventricular fibrillation threshold were determined in 17 closed-chest anesthetized pigs. IPC ranolazine increased atrial ERP in a time-dependent manner from 129 +/- 5.14 to 186 +/- 9.78 ms (P < 0.01, N = 7) but did not significantly affect ventricular ERP (from 188.3 +/- 4.6 to 201 +/- 4.3 ms (NS, N = 6). IPC ranolazine increased atrial fibrillation threshold from 4.8 +/- 0.8 to 28 +/- 2.3 mA (P < 0.03, N = 6) and ventricular fibrillation threshold (from 24 +/- 3.56 baseline to 29.33 +/- 2.04 mA at 10-20 minutes, P < 0.03, N = 6). No significant change in mean arterial pressure was observed (from 92.8 +/- 7.1 to 74.8 +/- 7.5 mm Hg, P < 0.125, N = 5, at 7 minutes). Conclusions: IPC ranolazine exhibits striking atrial antiarrhythmic actions as evidenced by increases in refractoriness and in fibrillation inducibility without significantly altering mean arterial blood pressure. Ranolazine`s effects on the atria appear to be more potent than those on the ventricles.

Validation of a Cutoff Value on Echo Doppler Analysis to Replace Right Heart Catheterization During Pulmonary Hypertension Evaluation in Heart Transplant Candidates

Background. Heart transplantation (OHT) has traditionally been contraindicated in the presence of severe pulmonary hypertension (PH), as detected by right heart catheterization. Noninvasive methods are still not reliably accurate to make this evaluation. Objectives. Determine the efficacy of echo Doppler analysis for the diagnosis of severe PH. Methods. One hundred thirty patients (mean age = 42 +/- 15 years, 82 men) showed severe left ventricular dysfunction (mean ejection fraction = 29 +/- 12%; functional class III-IV). We excluded patients with atrial fibrillation, heart failure secondary to congenital disease, and valvulopathy. The pulmonary parameters defined as severe PH were: systolic pulmonary artery pressure (sPAP) >= 60 mm Hg; a mean transpulmonary gradient >= 15; or pulmonary vascular resistance >= 5 Wood units. Patients underwent a right heart catheterization using a Swan-Ganz catheter to measure hemodynamic parameters and to noninvasively estimate right-sided pressures from spectral Doppler recordings of tricuspid regurgitation velocity (right ventricular systolic pressure [RVsP]). A Pearson correlation of sPAP was obtained with RVsP by; the sensitivity of RVsP for the diagnosis of PH was determined by a receiver operating characteristic (ROC) curve. Results. A good correlation between sPAP and RVsP was obtained by Pearson correlation analysis (r = 0.64; 95% confidence interval [CI] 0.50-0.75; P < .001). The ROC curve analysis showed a sensitivity of 100%, a specificity of 37.2%, (95% CI 0.69-0.83, P < .0001) of a RVsP < 45 mm Hg (cutoff) on the exclusion of severe PH. Conclusions. The cutoff of RVsP < 45 mm Hg, on noninvasive echo Doppler evaluation of PH is an efficient method to replace invasive heart catheterization in OHT candidates.

Dobutamine Stress Echocardiography in Heart Transplant Recipients` Evaluation: The Role of Reinnervation

Introduction. Orthotopic heart transplantation renders the recipient denervated. This remodeling of the intrinsic cardiac nervous system should be taken in account during functional evaluation for allograft coronary artery disease. Dobutamine stress echocardiography (DSE) has been used to detect patients at greater risk. The aim of this study was to determine whether patients with various autonomic response levels, and supposed reinnervation patterns, show the same response to DSE. Methods. We studied 20 patients who had survived more than 5 years after orthotopic heart transplantation. All patients underwent a Holter evaluation. We considered patients with low variability to be those with less than a 40-bpm variation from the lowest to highest heart rate, so-called ""noninnenervated"" (group NI). Patients who had 40-bpm or more variation were considered to show high variability and called ""reinnervated"" (group RI). After that, all patients performed an ergometric test and DSE. Results. Groups were defined as NI (n = 9) and RI (n = 11). Ergometric tests confirmed this response with NI patients showing less variability when compared to RI patients (P = .0401). During DSE, patients showed similar median heart rate responses according to the dobutamine dose. Spearmen correlation showed r = 1.0 (P = .016). Conclusions: DES was effective to reach higher heart rates, probably related to catecholamine infusion. These findings may justify a better response when evaluating cardiac allograft vasculopathy in heart transplant patients.