Impact of Non-Pharmacological Interventions on the Mechanisms of Atherosclerosis.

Atherosclerosis remains the leading cause of mortality and morbidity worldwide characterized by the deposition of lipids and fibrous elements in the form of atheroma plaques in vascular areas which are hemodynamically overloaded. The global burden of atherosclerotic cardiovascular disease is steadily increasing and is considered the largest known non-infectious pandemic. The management of atherosclerotic cardiovascular disease is increasing the cost of health care worldwide, which is a concern for researchers and physicians and has caused them to strive to find effective long-term strategies to improve the efficiency of treatments by managing conventional risk factors. Primary prevention of atherosclerotic cardiovascular disease is the preferred method to reduce cardiovascular risk. Fasting, a Mediterranean diet, and caloric restriction can be considered useful clinical tools. The protective impact of physical exercise over the cardiovascular system has been studied in recent years with the intention of explaining the mechanisms involved; the increase in heat shock proteins, antioxidant enzymes and regulators of cardiac myocyte proliferation concentration seem to be the molecular and biochemical shifts that are involved. Developing new therapeutic strategies such as vagus nerve stimulation, either to prevent or slow the disease's onset and progression, will surely have a profound effect on the lives of millions of people.

Heart rate variability analysis and cardiac dysautonomia in ischemic stroke patients.

OBJECTIVES: Autonomic nervous system dysfunction after ischemic stroke predisposes to cardiovascular complications. We aimed to investigate cardiac autonomic activity in ischemic stroke patients using heart rate variability analysis, illustrating the sympathovagal balance at different sympathetic and parasympathetic activation tests. PATIENTS AND METHODS: We studied the dynamics of the linear and non-linear heart rate variability parameters in 31 left and 40 right middle cerebral artery ischemic stroke patients in rest condition and during autonomic activation tests (handgrip, standing, deep breathing and Valsalva maneuver). Data were compared with 30 age- and sex-matched healthy controls. RESULTS: We found different responses after autonomic activation tests in stroke patients depending on the cortical lateralization of the ischemic lesion. In resting state, left hemisphere stroke patients presented enhanced parasympathetic modulation of the heart rate (higher values for RMSSD, pNN50, HF and SD1, p < 0.05), comparing to right hemisphere stroke patients. This second group displayed a reduced cardiac parasympathetic control in resting state and during autonomic activation tests (handgrip and standing tests) compared to the left hemisphere stroke group and controls. Non-linear parameters SD1 and DFA α1 showed a decrease of variability and complexity of the heart rate in right hemisphere stroke patients, ameliorated during vagal activation tests. CONCLUSION: To prevent possible complications with vital risk, assessment of cardiovascular autonomic activity becomes a necessary stage in stroke patient management, facilitating immediate implementation of preventive and therapeutic strategies. Heart rate variability analysis in resting state and during autonomic activation tests allows identifying patients prone to sympathetic hyperactivity. New therapeutic perspectives for stroke management may emerge founded on the modulation of the autonomic nervous system.

Cortical modulation of cardiac autonomic activity in ischemic stroke patients.

The cardiovascular system is regulated by the autonomic nervous system, under cortical modulation. Stroke can induce cardiac autonomic imbalance, therefore, causing secondary cardiovascular complications. Heart rate variability (HRV) analysis is a simple method to appraise the autonomic nervous function. The purpose of this study was to investigate the cardiac autonomic activity in patients that suffered an ischemic stroke in middle cerebral artery (MCA) territory. Using Biopac Acquisition System, we monitored ECG in rest condition and during Ewing's tests. From these measurements, HRV parameters (using time and frequency domain analysis) were determined in 20 right MCA and 20 left MCA ischemic stroke patients, in the first 6 months after the acute event. Data were compared with 20 age- and sex-matched healthy controls. All the patients were right handed. In ischemic stroke patients, HRV parameters were significantly modified compared to controls (p < 0.05) and we found asymmetric responses to different stimulation autonomic tests between right and left hemisphere. Parameters illustrating the parasympathetic predominance in time domain (RMSSD) and frequency domain (HF) analysis were higher in left hemisphere stroke compared to right hemisphere stroke patients (p < 0.01) in resting state. From Ewing's battery test, patients with left hemisphere ischemic stroke showed predominance of parasympathetic activity to deep breathing (p < 0.01), while HRV parameters in right hemisphere ischemic stroke patients described a reduced cardiac parasympathetic innervation (p < 0.01). Cardiac autonomic imbalance occurs more often after right hemisphere ischemic stroke. HRV study may highlight cardiac dysfunctions that increase the risk of cardiovascular complications and portends a poor long-term outcome.

Echocardiographic predictors of adverse short-term outcomes after heart surgery in patients with mitral regurgitation and pulmonary hypertension.

BACKGROUND: Pulmonary hypertension (PH) is a frequent occurrence and a negative prognostic indicator in patients with mitral regurgitation. Preoperative PH causes higher early and late mortality rates after heart surgery, adverse cardiac events, and postoperative systolic dysfunction in the left ventricle (LV). METHODS: The research consisted of a retrospective study of a group of 171 consecutive patients with mitral regurgitation and preoperative PH who had undergone mitral valve surgery between January 2008 and October 2011. The PH diagnosis was based on echocardiographic evidence (systolic pulmonary artery pressure [sPAP] >35 mm Hg). The echocardiographic examination included assessment of the following: LV volume, LV ejection fraction (LVEF), sPAP, right ventricular end-diastolic diameter, right atrium area indexed to the body surface area, the ratio of the pulmonary acceleration time to the pulmonary ejection time (PAT/PET), tricuspid annular plane systolic excursion (TAPSE), determination of the severity of the associated tricuspid regurgitation, and presence of pericardial fluid. Surgical procedures consisted of mitral valve repair in 55% of the cases and mitral valve replacement in the remaining 45%. Concomitant coronary artery bypass grafting (CABG) surgery was carried out in 52 patients (30.41%), and De Vega tricuspid annuloplasty was performed in 29 patients (16.95%). The primary end point was perioperative mortality. The secondary end points included the following: pericardial, pleural, hepatic, or renal complications; the need for a new surgical procedure; postoperative mechanical ventilation >24 hours; length of stay in the intensive care unit; duration of postoperative inotropic support; need for an intra-aortic balloon pump; and need for pulmonary vasodilator drugs. RESULTS: The mortality rate was 2.34%. In the univariate analysis, the clinical and echocardiographic parameters associated with mortality were preoperative New York Heart Association (NYHA) class IV, the PAT/PET ratio, TAPSE, the indexed area of the right atrium, and concomitant CABG surgery. In the multivariate analysis, the indexed area of the right atrium and concomitant CABG surgery remained statistically significant. The multivariate analysis also showed the indexed area of the right atrium, LVEF, presence of pericardial fluid, preoperative NYHA class, and concomitant CABG surgery as statistically significant for the secondary end point. The receiver operating characteristic (ROC) curves identified an sPAP value >65 mm Hg to have the highest specificity and sensitivity for the risk of perioperative death in mitral regurgitation patients (area under the ROC curve [AUC], 0.782; P < .001) and identified an sPAP value of 60 mm Hg as the secondary end point (AUC, 0.82; P < .001). Severe PH (sPAP >60 mm Hg) is associated with a significant increase in the mortality rate; a longer stay in the intensive care unit; a mechanical ventilation duration >24 hours; lengthy inotropic support; renal, hepatic, and pericardial complications; and a need for endothelin receptor antagonists, phosphodiesterase type 5 inhibitors, and/or prostanoids, both in the general group and in patients with preserved systolic functioning of the left ventricle. CONCLUSIONS: PH is a strong short-term negative prognostic factor for patients with mitral regurgitation. The surgical procedure should be performed in the early stages of PH. Echocardiographic examination has useful, simple, and reproducible tools for classifying operative risks. An ischemic etiology and a need for concomitant CABG surgery are additional risk factors for patients with mitral regurgitation and PH.