Predictors of durable electrical isolation in the setting of second-generation cryoballoon ablation: A comparison between left superior, left inferior, right superior, and right inferior pulmonary veins.

AIM: The aim of this study is to assess specific per-vein procedural predictors of pulmonary vein (PV) late reconnection in cryoballoon ablation (CbA) METHODS AND RESULTS: We enrolled 148 consecutive patients undergoing a redo procedure after a previous index CbA in our center. A reconnection in at least one PV was found in 80 patients (54.1%) and the most frequently reconnected PV was the right inferior pulmonary vein (RIPV). Overall, pulmonary vein reconnection (PVr) was associated with longer time to -40°C (Tt-40°C) (54.4 ± 21.7 vs 67.6 ± 27.6 seconds; P < .001), warmer nadir temperature (NT) (-49.7°C ± 5.4°C vs -46.5°C ± 5.8°C; P < .001) and temperature at 60 seconds (-41.8°C ± 4.5°C vs -39.8°C ± 4.2°C; P < .001). The performance of these predictors differed between the veins. In particular, a comparable behavior was observed for left superior pulmonary vein (LSPV) and right superior pulmonary vein (RSPV), where NT ≤ -48°C showed a sensibility and a specificity, respectively, of 62% and 65% and 71% and 72% in predicting durable PV isolation. For RIPV, NT ≤ -48°C showed a sensitivity of 74% but low specificity (53%). Tt -40°C less than 60 seconds showed good negative predictive values, respectively, 83.9% for LSPV, 94.9% for left inferior pulmonary vein (LIPV), 90.2% for RSPV, and 82.7% for RIPV. Previous predictors cannot be used for LIPV. CONCLUSIONS: Freezing behavior and reconnection rates differ significantly among the four PVs. Freezing temperature parameters strongly predict late PVr in superior PVs and are slightly different in RIPV but can be applied as well. LIPV freezing behavior is the most different. Its reconnection is uncommon even in the subset of worse freezing temperatures and specific CB predictors cannot be identified.

Anatomic predictors of late right inferior pulmonary vein reconnection in the setting of second-generation cryoballoon ablation.

INTRODUCTION: The right inferior pulmonary vein (RIPV) accounts as the most frequently reconnected vein after pulmonary vein isolation using second-generation cryoballoon ablation (CB-A). Our objective was to assess anatomic predictors of late RIPV reconnection based on preprocedural computed tomography scan. METHODS: Patients with a repeat procedure for atrial tachyarrhythmia recurrence after index CB-A procedure were included. A total of 129 RIPVs were evaluated for ostial diameters, ostial area, and branching pattern. Interior angle between RIPV and horizontal line in the frontal/transversal plane was used to measure the RIPV orientation: RIPV frontal/transversal angle, respectively. In addition, interior angle between RIPV and the line perpendicular on the septal intersection line at the level of the fossa ovalis, estimated as trans-septal (TS) puncture site, was measured in the frontal/transversal view: RIPV-TS frontal/transversal angle, respectively. RESULTS: Late vein reconnection was present in 36/129 RIPVs (28%). Warmer balloon nadir temperature (P = .01), more inferior (P < .001) and posterior (P < .01) RIPV orientation (ie, more positive RIPV frontal and RIPV transversal angle, respectively), and sharper RIPV-TS frontal angle (P < .001) were associated with late RIPV reconnection on univariate analysis. Independent variables after multivariate analysis were nadir temperature (odds ratio [OR], 1.12; 95% confidence interval [CI], 1.03-1.23; P = .013) and RIPV frontal angle (OR, 1.13, CI, 1.07-1.19; P < .001). CONCLUSION: Frontal RIPV orientation could significantly predict late RIPV electrical reconnection after CB-A. Therefore, preprocedural anatomic assessment of the RIPV might be useful to plan the correct ablation strategy.

Nuclear assessment of right ventricle.

For many years, the right ventricle (RV) has been considered a passive chamber with a relatively insignificant role in the overall functionality of the heart. More recently, the role of performance of RV in the clinical presentation and long-term prognosis of multiple pathological states, such as congenital heart diseases, chronic heart failure, pulmonary hypertension, and chronic obstructive pulmonary disease. Despite echocardiography and cardiac magnetic resonance are the 2 most commonly used imaging techniques for noninvasive assessment of RV, nuclear imaging provides new opportunities for comprehensive evaluation of RV from a single study, because it can assess right ventricular perfusion and metabolism as well as morphology and ejection fraction. In this review, we summarize the application of radionuclide techniques (nuclear cardiology) for evaluation of the RV, focusing on its emerging role in the assessment of right ventricular perfusion and metabolism.

Molecular aspects of the cardioprotective effect of exercise in the elderly.

Aging is a well-recognized risk factor for several different forms of cardiovascular disease. However, mechanisms by which aging exerts its negative effect on outcome have been only partially clarified. Numerous evidence indicate that aging is associated with alterations of several mechanisms whose integrity confers protective action on the heart and vasculature. The present review aims to focus on the beneficial effects of exercise, which plays a pivotal role in primary and secondary prevention of cardiovascular diseases, in counteracting age-related deterioration of protective mechanisms that are crucially involved in the homeostasis of cardiovascular system. In this regard, animal and human studies indicate that exercise training is able: (1) to improve the inotropic reserve of the aging heart through restoration of cardiac ß-adrenergic receptor signaling; (2) to rescue the mechanism of cardiac preconditioning and angiogenesis whose integrity has been shown to confer cardioprotection against ischemia and to improve post-myocardial infarction left ventricular remodeling; (3) to counteract age-related reduction of antioxidant systems that is associated to decreased cellular resistance to reactive oxygen species accumulation. Moreover, this review also describes the molecular effects induced by different exercise training protocols (endurance vs. resistance) in the attempt to better explain what kind of exercise strategy could be more efficacious to improve cardiovascular performance in the elderly population.

N-terminal pro-b-type natriuretic peptide and left atrial function in patients with congestive heart failure and severely reduced ejection fraction.

AIMS: Amino-terminal portion of pro-B-type natriuretic peptide (NT-pro-BNP) is a valuable diagnostic and prognostic marker in congestive heart failure (CHF). In CHF patients, elevation of natriuretic peptide levels correlate with decreased left ventricular (LV) ejection fraction (EF) and increased left atrial (LA) volumes, but a correlation with LA function that is a determinant of haemodynamic and clinical status in CHF with independent prognostic value has never been investigated. Aim of this study was to evaluate the relationship between cardiac neurohormonal activation and LA function in patients with CHF due to dilated cardiomyopathy. METHODS AND RESULTS: One hundred and one patients (86% males; mean age, 64 ± 11 years) with dilated ischaemic or non-ischaemic cardiomyopathy, LV EF ≤45% (mean LV EF, 33 ± 8%), and New York Heart Association class II-IV underwent transthoracic echocardiography to evaluate LA fractional active and total emptying from M- and B-Mode images, and, on the same day, venous blood sample collection to dose NT-pro-BNP. By univariate analyses, NT-pro-BNP significantly correlated to age, LA dimensions, LA function indexes, EF, and functional class. At multivariate analysis, LV EF and M- or B-Mode indexes of LA function were the only independent predictors of NT-pro-BNP values. A NT-pro-BNP cut-off of 1480 pg/mL identified LA dysfunction with 89% specificity and 54% sensitivity. CONCLUSION: In CHF patients with severely impaired systolic function, NT-pro-BNP levels reflect LA and LV dysfunction. These data should prompt studies to investigate the relationship between changes of LA function and NT-pro-BNP levels and their clinical value as prognostic and therapeutic targets in CHF.

Electrocardiographic imaging of the arrhythmogenic substrate of Brugada syndrome: Current evidence and future perspectives.

Brugada syndrome is responsible for about 20% of sudden cardiac deaths in patients with apparently normal hearts. Basic and clinical research has elucidated some of the mechanisms that are responsible for life-threatening ventricular arrhythmias in this syndrome. Delays in activation and repolarization over the right ventricular outflow tract are the most likely cause of the ECG typical pattern and arrhythmogenesis. Invasive epicardial and endocardial mapping has identified the epicardium as the principal region of interest for these anomalies, and areas of fragmented potentials at invasive mapping are a target for epicardial ablation. Noninvasive mapping systems have been developed to study the epicardial depolarization and repolarization and may be particularly useful in assessing the epicardial arrhythmogenic substrate of Brugada syndrome for both clinical and research purpose. This review focuses on recent advances in this field.

High parasympathetic activity as reflected by deceleration capacity predicts atrial fibrillation recurrence after repeated catheter ablation procedure.

PURPOSE: High parasympathetic nervous system (PNS) activity is accurately reflected by deceleration capacity (DC) and is involved in atrial fibrillation (AF) recurrence after catheter ablation procedure. When compared with initial catheter ablation procedure, repeated procedures for AF recurrence are followed by a lower success rates, estimated at 50%. Our objective was to evaluate the impact of PNS activity assessed by DC measured before repeated procedure on AF recurrence after repeated procedure. METHODS: Consecutive patients who underwent an initial catheter ablation procedure for pulmonary vein (PV) isolation and a repeated catheter ablation procedure for AF recurrence were selected. Additional 24-h ambulatory electrocardiographic recording between procedures for DC measurement was required for inclusion. A total of 110 patients were included. Seventy-two patients underwent cryoballoon (CB) ablation and 38 patients underwent radiofrequency (RF) ablation as initial procedure, while all patients underwent RF ablation as repeated procedure. RESULTS: DC was higher in cases with right-sided PV reconnection (p = 0.04, OR = 1.38, 95% CI = 1.08-1.78). In patients with CB ablation as initial procedure, DC was higher in patients with PV reconnection (p = 0.03, OR = 1.29, 95% CI = 1.11-1.70), and the number of reconnected PVs was higher in patients with DC ≥ 7.0 ms (median DC value used for dichotomization, p = 0.02, OR = 2.19, 95% CI = 1.10-4.37). In multivariate Cox regression, DC predicted AF recurrence after repeated ablation (p = 0.004, HR = 1.68, 95% CI = 1.35-1.82). In multivariate binary regression, DC predicted persistent AF type recurrence after repeated ablation (p = 0.01, OR = 1.50, 95% CI = 1.10-2.02). CONCLUSIONS: DC is a novel predictor of AF recurrence and AF recurrence type after repeated catheter ablation procedure. DC may reflect the need of more intensive treatment strategies in patients with high PNS activity.

Conversion of atrial fibrillation to sinus rhythm during cryoballoon ablation: A favorable and not unusual phenomenon during second-generation cryoballoon pulmonary vein isolation.

BACKGROUND: The prevalence and the clinical impact of conversion of atrial fibrillation (AF) to sinus rhythm (SR) during cryoballoon ablation (CB-A) are unknown. OBJECTIVE: The purpose of this study was to evaluate the prevalence of restoration of SR during CB-A and the clinical impact of this phenomenon. METHODS: Between January 2012 and September 2018, all patients who experienced conversion of AF to SR during CB-A were included. This group was subsequently matched for gender, age, type of AF, diagnosis-to-ablation time, and left atrial size with patients who underwent CB-A and did not experienced conversion of AF to SR. After discharge, patients were scheduled for follow-up visits at 1, 3, 6, and 12 months and 24 hours Holter recordings were obtained at each follow-up visit. All documented AF episodes of >30 seconds were considered as recurrence. A 3 month post-procedural blanking period (BP) was applied. RESULTS: A total of 1559 patients underwent pulmonary veins isolation by CB-A between January 2012 and September 2018; among them, 58 patients (3.7%) experienced restoration of SR during CB-A. In total, 53 patients (41 males [77.3%], mean age 61.4 ± 13.3 years) were included in the case group. During CB-A, restoration of SR occurred more frequently during right-side PVs applications (right inferior pulmonary vein 39.6%, right superior pulmonary vein 30.2%). If considering a BP, at 2 year follow-up, freedom from recurrences was 86.5% in the case group and 68.0% in the control group (P = .036). CONCLUSION: Conversion of AF to SR is a favorable and relatively frequent phenomenon during cryoballoon pulmonary vein isolation ablation.

Standardized Quantification of Vagal Denervation by Extracardiac Vagal Stimulation during Second Generation Cryoballoon ablation: a Vein per Vein Analysis.

AIMS: The purpose of this study was to evaluate the contribution in the acute loss in vagal innervation after ablation with the second generation cryoballoon (CB-A) in each distinct pulmonary vein (PV) by means of external cardiac vagal stimulation (ECVS) by positioning a catheter in the internal jugular vein in a cohort of 60 patients. METHODS: Sixty patients, 50 starting from the left superior pulmonary vein (LSPV) and 10 from the right superior pulmonary vein with symptomatic paroxysmal atrial fibrillation (PAF), having undergone ECVS before the first and after each PV ablation by means of CB-A ablation, were included. RESULTS: The ECVS performed pre-ablation provoked cardioinhibitory responses in all cases with mean pause duration of 10251.83 ms ± 2826.23 ms. At the end of the procedure, the vagal reactions (VR) were significantly diminished. Specifically, compared against the initial pause, responses were 8957.06 ± 2711.66 ms (p < 0.01) after left superior PV, 10017.36 ± 9127.0 ms (p = 0.88) after left inferior PV, 6020.16 ± 3780.709 ms (p < 0.001) after right inferior PV and 1687.5 ± 2183.7 ms (p < 0.001) after right superior PV. Noteworthy, if starting with ablation in the RSPV, VR was immediately reduced by 90.34%, 990.7 ± 379.78 ms (p < 0.001) as compared to baseline response. CONCLUSION: Although not directly targeting the ganglion plexuses, AF ablation with the CB-A causes a significant acute loss in parasympathetic innervation. The RSPV showed to be associated with the most significant reduction of acute loss in parasympathetic innervation.

[The role of myocardial scintigraphy in the assessment of coronary artery disease]. / Il ruolo della scintigrafia miocardica nella valutazione della cardiopatia ischemica.

Single photon emission computed tomography (SPECT) for the assessment of myocardial perfusion was introduced in the early 1970s, following pioneer studies of Gould et al. It has rapidly become one of the most used noninvasive technique for the assessment of myocardial ischemia. Thanks to the current technetium based tracers that allow electrocardiogram gated synchronization, it is possible to assess the regional ventricular systolic function and the evaluation of myocardial perfusion as well. In the last twenty years, beyond its diagnostic role, myocardial SPECT has become also a prognostic technique. Indeed, it has acquired a role for the short-term prediction of major coronary events in a large cohort with known or suspected coronary artery disease (CAD). The aim of this review is to give an update of the correct use and interpretation of myocardial SPECT in patients with known or suspected CAD and without left ventricular dysfunction.

Sleep-disordered breathing, impaired cardiac adrenergic innervation and prognosis in heart failure.

OBJECTIVE: Unfavourable effects of sleep-disordered breathing (SDB) in heart failure (HF) are mainly mediated by impaired sympathetic activity. Few data are available on SDB and cardiac adrenergic impairment evaluated at myocardial level. The aim of the study was to assess the relationship between SDB, cardiac sympathetic innervation assessed by 123I-metaiodobenzylguanidine (123I-MIBG) imaging and prognosis in HF. METHODS: Observational, prospective study enrolling patients with HF and reduced systolic function. Patients underwent nocturnal cardiorespiratory monitoring to assess SDB presence by apnoea/hypopnoea index (AHI), and 123I-MIBG imaging to calculate heart-to-mediastinum (H/M) ratios and washout rate. Patients were prospectively followed for 29±18 months for the combined endpoint of cardiovascular death and HF hospitalisation. RESULTS: Ninety-four patients (66.1±9.8 years; left ventricular ejection fraction 32±7%) were enrolled; 72 (77%) showed SDB and, compared with non-SDB, significantly reduced early (1.67±0.22 vs 1.77±0.13; p=0.019) and late H/M ratios (1.50±0.22 vs 1.61±0.23; p=0.038). Dividing patients into two groups according to SDB severity, patients with a moderate-severe disturbance (AHI >15; n=43) showed significantly worse survival for the composite study outcome (log-rank test, p=0.001) with respect to patients with mild or no disorder (AHI ≤15; n=51). Adding SDB variables to the already known prognostic role of 123I-MIBG imaging, we observed a worse survival in patients with both SDB and H/M impairment. CONCLUSIONS: Patients with systolic HF and SDB show more impaired cardiac adrenergic innervation assessed by 123I-MIBG imaging, and more adverse prognosis compared with HF patients without SDB.

Benefits of statins in elderly subjects without established cardiovascular disease: a meta-analysis.

OBJECTIVES: The purpose of this paper was to assess whether statins reduce all-cause mortality and cardiovascular (CV) events in elderly people without established CV disease. BACKGROUND: Because of population aging, prevention of CV disease in the elderly is relevant. In elderly patients with previous CV events, the use of statins is recommended by guidelines, whereas the benefits of these drugs in elderly subjects without previous CV events are still debated. METHODS: Randomized trials comparing statins versus placebo and reporting all-cause and CV mortality, myocardial infarction (MI), stroke, and new cancer onset in elderly subjects (age ≥ 65 years) without established CV disease were included. RESULTS: Eight trials enrolling 24,674 subjects (42.7% females; mean age 73.0 ± 2.9 years; mean follow up 3.5 ± 1.5 years) were included in analyses. Statins, compared with placebo, significantly reduced the risk of MI by 39.4% (relative risk [RR]: 0.606 [95% confidence interval (CI): 0.434 to 0.847]; p = 0.003) and the risk of stroke by 23.8% (RR: 0.762 [95% CI: 0.626 to 0.926]; p = 0.006). In contrast, the risk of all-cause death (RR: 0.941 [95% CI: 0.856 to 1.035]; p = 0.210) and of CV death (RR: 0.907 [95% CI: 0.686 to 1.199]; p = 0.493) were not significantly reduced. New cancer onset did not differ between statin- and placebo-treated subjects (RR: 0.989 [95% CI: 0.851 to 1.151]; p = 0.890). CONCLUSIONS: In elderly subjects at high CV risk without established CV disease, statins significantly reduce the incidence of MI and stroke, but do not significantly prolong survival in the short-term.

Endothelial dysfunction in type 2 diabetic patients with normal coronary arteries: a digital reactive hyperemia study.

BACKGROUND: To assess endothelial function (EF) in type 2 diabetic patients with angiographically normal coronaries compared to diabetic patients with obstructive coronary artery disease (CAD) and to non-diabetic patients, with and without CAD. METHODS: One hundred eighty-three patients undergoing coronary angiography were divided in: group 1 with diabetes mellitus (DM) and CAD (n = 58); group 2 with DM without CAD (n = 58); group 3 with CAD without DM (n = 31) and group 4 without CAD and DM (n = 36). EF was assessed by reactive hyperemia index (RHI) using a fingertip peripheral arterial tonometry and compared to values obtained in 20 healthy volunteers. RESULTS: RHI was significantly lower in patients with DM compared to patients without DM (1.69 ± 0.38 vs 1.84 ± 0.44; p = 0.019). RHI was comparable among groups 1, 2 and 3, each value being significantly lower compared to group 4 (2 ± 0.44; p<0.001 vs group 1; p<0.005 vs group 2; p<0.002 vs group 3). At multivariate analysis DM and CAD were significant predictors of endothelial dysfunction (ED) (OR = 2.29; p = 0.012; OR = 2.76; p = 0.001, respectively), whereas diabetic patients (n = 116) CAD and glycated haemoglobin (HbA1c) were independent significant predictors of ED (OR = 3.05; p = 0.009; OR = 1.96; p = 0.004, respectively). Diabetic patients with ED (n = 67) had higher levels of HbA1c than diabetic patients with normal endothelial function (7.35 ± 0.97 vs 6.87 ± 0.90; p = 0.008) and RHI inversely correlated to HbA1c (p = 0.02; r = -0.210). CONCLUSIONS: Diabetic patients with and without CAD show significantly impaired peripheral vascular function compared to non-diabetic patients without CAD. ED in diabetic patients without CAD is comparable to that of patients with CAD but without DM. HbA1c is a weak independent predictor of ED.

The prognostic value of normal stress cardiac magnetic resonance in patients with known or suspected coronary artery disease: a meta-analysis.

BACKGROUND: Ischemia detection with stress cardiac magnetic resonance (CMR) is typically based on induction of either myocardial perfusion defect or wall motion abnormality. Single-center studies have shown the high value of stress CMR for risk stratification. The aim of this study was to define the prognostic value of stress CMR for prediction of adverse cardiac events in patients with known or suspected coronary artery disease. METHODS AND RESULTS: Studies published between January 1985 and April 2012 were identified by database search. We included studies using stress CMR to evaluate subjects with known or suspected coronary artery disease and providing primary data on clinical outcomes of nonfatal myocardial infarction or cardiac death with a follow-up time ≥3 months. Total of 14 studies were finally included, recruiting 12 178 patients. The negative predictive value for nonfatal myocardial infarction and cardiac death of normal CMR was 98.12% (95% confidence interval, 97.26-98.83) during a weighted mean follow-up of 25.3 months, resulting in estimated event rate after a negative test equal to 1.88% (95% confidence interval, 1.17-2.74). The corresponding annualized event rate after a negative test was 1.03%. Comparable negative predictive values for major coronary events were obtained in studies considering the absence of inducible perfusion defect compared with those evaluating the absence of inducible wall motion abnormality (98.39% versus 97.31%, respectively; P=0.227 by meta-regression analysis). CONCLUSIONS: Stress CMR has a high negative predictive value for adverse cardiac events, and the absence of inducible perfusion defect or wall motion abnormality shows a similar ability to identify low-risk patients with known or suspected coronary artery disease.

Vascular endothelial growth factor blockade prevents the beneficial effects of ß-blocker therapy on cardiac function, angiogenesis, and remodeling in heart failure.

BACKGROUND: Impaired angiogenesis in the post-myocardial infarction heart contributes to the progression to heart failure. The inhibition of vascular endothelial growth factor (VEGF) signaling has been shown to be crucial for the transition from compensatory hypertrophy to cardiac failure. Importantly, ß-adrenergic receptor blocker therapy has been also shown to improve myocardial perfusion by enhancing neoangiogenesis in the failing heart. METHODS AND RESULTS: Eight weeks from surgically induced myocardial infarction, heart failure rats were randomized to receive bisoprolol (B) or vehicle. At the end of a 10-week treatment period, echocardiography revealed reduced cardiac diameters and improved cardiac function in B-treated compared with vehicle-treated rats. Moreover, B treatment was associated with increased cardiac angiogenesis and in vivo coronary perfusion and reduced cardiac fibrosis. Importantly, 2 weeks after B treatment was started, increased cardiac VEGF expression and Akt and endothelial NO synthase activation were observed by comparing B-treated with drug-untreated failing hearts. To test whether the proangiogenic effects of B act via activation of VEGF pathway, rats were intravenously injected with adenoviral vector encoding a decoy VEGF receptor (Ad-Flk) or a control adenovirus (Ad-C), at the start of the treatment with B. After 10 weeks, histological analysis revealed reduced capillary and coronary perfusion in B-treated plus Ad-Flk rats compared with B-treated plus Ad-C rats. Moreover, VEGF inhibition counteracted the positive effects of B on cardiac function and remodeling. CONCLUSIONS: ß-Blockade promotes cardiac angiogenesis in heart failure via activation of VEGF signaling pathway. ß-Blocker-induced enhancement of cardiac angiogenesis is essential for the favorable effects of this therapy on cardiac function and remodeling.

Coronary computed tomography: current role and future perspectives for cardiovascular risk stratification.

Coronary artery disease (CAD) is the major cause of morbidity and mortality worldwide. More than 50% of CAD deaths occur in previously asymptomatic individuals at intermediate cardiovascular risk, highlighting the need of more accurate individual risk assessment to decrease cardiovascular events. Cardiac computed tomography (CCT) has emerged as a valuable technique for risk stratification in asymptomatic subjects and in symptomatic patients without known CAD. The absence of coronary artery calcium (CAC) identifies asymptomatic subjects at very low cardiac risk and is reasonable in intermediate risk individuals, in whom CAC measurement reclassifies a substantial number of subjects to different risk categories. In symptomatic patients with suspected CAD, detection of non-obstructive or obstructive CAD by CCT angiography is associated with increased all-cause mortality, and provides incremental risk stratification to CAC. Further studies are needed to assess the impact of CCT on clinical outcomes and its cost-effectiveness in different clinical settings.

[Sleep apnea and heart failure: pathophysiology, diagnosis and therapy]. / Apnee notturne e scompenso cardiaco: fisiopatologia, diagnosi e terapia.

Sleep apnea, defined as a pathologic pause in breathing during sleep >10 s, promotes the progression of chronic heart failure and may be a predictor of poor prognosis. It causes, in fact, several mechanical, hemodynamic, chemical and inflammatory changes that negatively compromise cardiovascular homeostasis of heart failure patients. Sleep apnea is recognized as sleep apnea syndrome when specific symptoms, such as sleepiness and headache during the daytime and snoring, are present and is diagnosed with an overnight test called polysomnography. There are two different forms of sleep apnea, central and obstructive. Breathing is interrupted by the loss of respiratory drive and the lack of respiratory effort in the central form, which affects about 40-60% of heart failure patients. In obstructive sleep apnea, breathing stops when throat muscles relax, despite respiratory effort. This form affects about 3% of the general population, while it is present in at least 30% of heart failure patients. The diagnosis of sleep disorders in heart failure becomes very important to help patients adopting lifestyle changes and starting specific therapies to improve quality of life and retard the progression of chronic heart failure.

Cardiovascular effects of antiretroviral drugs: clinical review.

In HIV infected patients an increased occurence of cardiac events has been demontrated from the introduction of highly active antiretroviral therapy (HAART). Antiretroviral drugs' regimens are, in fact, associated with several metabolic side effects, such as dyslipidemia, impaired glucose metabolism and abnormal body fat distribution, that increase the cardiovascular risk of HIV subjects. In addition, HIV infection itself, the chronic inflammatory status and the relevant presence in this population of some of the traditional cardiovascular risk factors contribute to an higher incidence of cardio and cerebrovascular events. In last years several studies showed the occurence of carotid vascular impairment in patients in treatment with protease inhibitors (PI). Similarly the DAD Study reported an increase of 26% of the risk of myocardial infarction in patients on HAART and that this risk is indipendently associated with longer exposure to PI, even after multivariate adjustments. A correct evaluation of the metabolic status before starting HAART and an adeguate control of the drugs-related metabolic abnormalities may reduce the incidence of cardiac events and still improve HIV patients prognosis. This review will focus on the metbolic effects of antiretroviral drugs and to the contribution of combination antiretroviral therapy on cardiovascular risk.