The Prevalence of Orthostatic Hypotension in Cancer Patients.

BACKGROUND: Orthostatic hypotension (OH) is associated with a higher risk of mortality in the general population; however, it has not been studied in the cancer population. This study aimed to assess the prevalence of OH in cancer patients compared to that in the noncancer population. METHODS: A total of 411 patients (mean age 63.5 ± 10.6 years) were recruited: patients with active cancer (n = 223) and patients hospitalised for other reasons, but without a cancer diagnosis (n = 188). Medical histories were collected and an orthostatic challenge test was performed. OH was defined as a blood pressure (BP) decrease upon standing of ≥20 mmHg for the systolic or ≥10 mmHg for the diastolic BP after 1 or 3 min; or a systolic BP decrease <90 mmHg. RESULTS: The prevalence of OH in the subjects with cancer was significantly higher than in the subjects without cancer (28.7% vs. 16.5%, respectively, p = 0.003). OH was the most common in the lung cancer patients (57.5%). In a single-variable analysis, the predictors of OH were cancer presence, age ≥ 65 years, and body mass index (BMI) ≥ 30 kg/m2. In the multivariable model, the strongest independent predictor of OH was cancer status, which doubled the risk of OH, and BMI ≥ 30 kg/m2 and diabetes. CONCLUSIONS: Cancer patients are characterised by a high prevalence of OH. In this population, the recommendation of routine orthostatic challenge tests should be considered.

A COVID-19 Diagnosis Like an Avalanche Triggers a Series of Adverse Events but Saves a Life in the End.

Patients diagnosed with cancer are less frequently covered by preventive measures for cardiovascular diseases. The frequent co-occurrence of these diseases makes it necessary to apply parallel diagnostics and cardiological treatment with anti-cancer therapy. Frequently. multidisciplinary team discussions are needed. Case report: We present a case of a 73-year-old former smoker with hyperlipidemia, type 2 diabetes, and arterial hypertension, after a partial right nephrectomy in 2005 due to kidney cancer, diagnosed with SARS-CoV-2 infection in April 2022. Subsequent chest imaging showed a 20 mm focal lesion in the left lung further classified as a small-cell neuroendocrine carcinoma. Unexpectedly, the patient was hospitalized due to ST-segment elevation inferior left ventricular (LV) myocardial infarction. It was treated successfully with percutaneous coronary angioplasty (PCI) of the circumflex and first marginal artery with drug-eluting stent (DES) implantation. One day later, PCI of the left anterior artery was performed with two DES implantation; however, heart failure (HF) with a reduced left ventricle ejection fraction of 30% was diagnosed. One month later, the patient required hospitalization again due to HF decompensation, and cardiological treatment was optimized with flozin in addition to standard HF therapy. Subsequently, after cardiological approval the patient qualified for chemotherapy with the cisplatin-etoposide regimen. Therapy was continued for 6 months without HF decompensation and significant deterioration in renal function. After that, the patient underwent radical radiotherapy. Follow-up chest computed tomography scans showed regression of the neoplastic lesion. Conclusions: The coincidence of newly recognized cancer and inflammatory disease might contribute to and provoke serious cardiological events. To reduce the risk of cardiovascular complications, periodic cardiological surveillance and optimal pharmacotherapy are required.

Implementation of zero or near-zero fluoroscopy catheter ablation for idiopathic ventricular arrhythmia originating from the aortic sinus cusp.

Complete elimination of fluoroscopy during radiofrequency ablation (RFA) of idiopathic ventricular arrhythmias (IVAs) originating from the aortic sinus cusp (ASC) is challenging. The aim was to assess the feasibility, safety and a learning curve for a zero-fluoroscopy (ZF) approach in centers using near-zero fluoroscopy (NOX) approach in IVA-ASC. Between 2012 and 2018, we retrospectively enrolled 104 IVA-ASC patients referred for ZF RFA or NOX using a 3-dimensional electroanatomic (3D-EAM) system (Ensite, Velocity, Abbott, USA). Acute, short and long-term outcomes and learning curve for the ZF were evaluated. ZF was completed in 62 of 75 cases (83%) and NOX in 32 of 32 cases (100%). In 13 cases ZF was changed to NOX. No significant differences were found in success rates between ZF and NOX, no major complications were noted. The median procedure and fluoroscopy times were 65.0 [45-81] and 0.0 [0-5] min respectively, being shorter for ZF than for NOX. With growing experience, the preference for ZF significantly increased-43% (23/54) in 2012-2016 vs 98% (52/53) in 2017-2018, with a simultaneous reduction in the procedure time. ZF ablation can be completed in almost all patients with IVA-ASC by operators with previous experience in the NOX approach, and after appropriate training, it was a preferred ablation technique. The ZF approach for IVA-ASC guided by 3D-EAM has a similar feasibility, safety, and effectiveness to the NOX approach.

Clinical presentation and treatment of acute coronary syndrome as well as 1-year survival of patients hospitalized due to cancer: A 7-year experience of a nonacademic center.

The diagnosis of acute coronary syndrome (ACS) in patients with cancer constitutes a therapeutic challenge. We aimed to assess the clinical presentation and management of ACS as well as 1-year survival in patients hospitalized for cancer.This retrospective study included patients hospitalized between 2012 and 2018 in a nonacademic center. The inclusion criteria were diagnosis of active cancer and ACS recognized using standard criteria. Patients were assessed with respect to invasive or conservative ACS strategy. The primary endpoint was all-cause mortality, and the secondary endpoint was cardiovascular mortality during 1-year follow-up.We screened 25,165 patients, of whom 36 (0.14%) had ACS (mean [SD] age, 71.9 [9.8] years). The most common presentation was non-ST-segment elevation myocardial infarction (61% of patients). Coronary angiography was performed in 47% of patients, while 53% were treated conservatively. Overall, the primary endpoint occurred in 67% of patients and secondary endpoint in 28% during follow-up. The predictors of better outcome in a univariate analysis were invasive strategy, lack of metastases, aspirin use, and no cardiogenic shock. Invasive treatment and aspirin use remained significant predictors of better survival when adjusted for the presence of metastases (hazard ratio [HR] 0.37, confidence interval [CI] 0.15-0.92 and HR 0.39, CI 0.16-0.94, respectively) and ineligibility for cancer treatment (HR 0.37, CI 0.15-0.93 and HR 0.30, CI 0.12-0.73, respectively).The incidence of ACS in cancer patients is low but 1-year mortality rates are high. Guideline-recommended management was frequently underused. Our results suggest that invasive approach and aspirin use are associated with better survival regardless of cancer stage and eligibility for cancer treatment.

Renal denervation in patients with symptomatic chronic heart failure despite resynchronization therapy - a pilot study.

INTRODUCTION: Renal denervation (RD) has been shown to decrease sympathetic function in patients with hypertension. Its efficacy in symptomatic chronic heart failure (CHF) patients not responding to cardiac resynchronization therapy (CRT) has not been evaluated. AIM: To assess whether a less invasive treatment method - renal denervation - is safe in symptomatic heart failure patients despite optimal medical treatment and resynchronization therapy and whether it is associated with an improvement in clinical status, exercise capacity and hemodynamic parameters. MATERIAL AND METHODS: The study was an open-label, randomized, controlled clinical trial. Patients were divided into an intervention (RD) and a control group. Clinical data collection, blood pressure (BP) measurements, echocardiography, 6-minute walk test (6MWT) and laboratory tests were performed before, 6 and 12 months after RD. The patients were followed-up to 24 months. RESULTS: We included 20 patients aged 52.0 to 86.0 years (median age: 71.5 years), 15 males and 5 females with median left ventricular ejection fraction (LVEF) of 32.5%, body mass index 31.3 kg/m2. Renal denervation was safe, no significant adverse effects were registered. There were no significant differences in LVEF, BP, 6MWT and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentration 6 and 12 months after RD or control. CONCLUSIONS: Our results indicate that RD in CHF patients not responding to CRT is safe and does not worsen exercise capacity and hemodynamic parameters.

Long-term follow-up and comparison of techniques in radiofrequency ablation of ventricular arrhythmias originating from the aortic cusps (AVATAR Registry).

INTRODUCTION: Radiofrequency ablation (RFA) of outflow tract ventricular arrhythmia (VA) that originates from the aortic cusps can be challenging. Data on long­ term efficacy and safety as well as optimal technique after aortic cusp ablation have not previously been reported. OBJECTIVES: This aim of the study was to determine the short- and long­ term outcomes after RFA of aortic cusp VA, and to evaluate aortic valve injuries according to echocardiographic screening. PATIENTS AND METHODS: This was a prospective multicenter registry (AVATAR, Aortic Cusp Ventricular Arrhythmias: Long Term Safety and Outcome from a Multicenter Prospective Ablation Registry) study. A total of 103 patients at a mean age of 56 years (34-64) from the "Electra" Registry (2005-2017) undergoing RFA of aortic cusps VA were enrolled. The following 3 ablation techniques were used: zero­fluoroscopy (ZF; electroanatomical mapping [EAM] without fluoroscopy), EAM with fluoroscopy, and conventional fluoroscopy­ based RFA. Data on clinical history, complications after RFA, echocardiography, and 24­ hour Holter monitoring were collected. The follow up was 12 months or longer. RESULTS: There were no major acute cardiac complications after RFA. In one case, a vascular access complication required surgery. The median (interquartile range [IQR]) procedure time was 75 minutes (IQR, 58-95), median follow­ up, 32 months (IQR, 12-70). Acute and long term procedural success rates were 93% and 86%, respectively. The long­ term RFA outcomes were observed in ZF technique (88%), EAM with fluoroscopy (86%), and conventional RFA (82%), without differences. During long­ term follow­up, no abnormalities were found within the aortic root. CONCLUSIONS: Ablation of VA within the aortic cusps is safe and effective in long­ term follow up. The ZF approach is feasible, although it requires greater expertise and more imaging modalities.

Cardiac autonomic regulation in patients undergoing pulmonary vein isolation for atrial fibrillation.

AIMS: Ablation procedures for the treatment of atrial fibrillation lead to changes in autonomic heart control; however, there are insufficient data on the possible association of these changes with atrial fibrillation recurrence. The study aim was to assess the effects of pulmonary vein isolation (PVI) on cardiac autonomic modulation and atrial fibrillation recurrence. METHODS: We screened 52 patients with atrial fibrillation referred for PVI, of whom 20 patients met inclusion and exclusion criteria, and were enrolled in the study and followed over 6 months. Beat-to-beat blood pressure monitoring was performed 1-2 days before PVI, 1 and 6 months after PVI. We estimated pulse interval variability and spontaneous baroreflex sensitivity (BRS) both in the time and frequency domains, and performed the Valsalva manoeuvre assessing the Valsalva ratio. RESULTS: During 6 months after PVI, atrial fibrillation recurrence was observed in six patients. One month after PVI, pulse interval variability and BRS (sequence method) significantly decreased in all patients, returning to preintervention values by 6 months. Patients without atrial fibrillation recurrence at 1 month showed a transient reduction in pulse interval variability (frequency domain) and in BRS (both methods) in contrast to those with atrial fibrillation recurrence. A significant decrease in the Valsalva ratio observed at 1 month was maintained at 6 months after PVI in both groups. CONCLUSION: Successful PVI may lead to transient autonomic alterations reflected by a reduction in pulse interval variability and BRS, with more prolonged changes in the Valsalva ratio. The efficacy of PVI in preventing atrial fibrillation recurrence seems to be related to transient parasympathetic atrial denervation.

Effects of device­guided slow breathing training on exercise capacity, cardiac function, and respiratory patterns during sleep in male and female patients with chronic heart failure.

INTRODUCTION Slow breathing training (SBT) has been proposed as a new nonpharmacologic treatment in patients with chronic heart failure (CHF). OBJECTIVES The aim of this study was to assess the effects of SBT on exercise capacity, hemodynamic parameters, and sleep respiratory patterns in a relatively large sample of CHF patients. PATIENTS AND METHODS A crossover open study was conducted. Patients completed, in a random order, 10- to 12­week SBT, with 2 15­minute sessions of device­guided SBT each day, reaching 6 breaths/ min, and a 10- to 12­week follow­up under standard care. Clinical data collection, polysomnography, echocardiography, 6­minute walk test (6MWT), and laboratory tests were performed. RESULTS A total of 96 patients (74 men, 22 women) in New York Heart Association classes I-III, with an average age of 65 years and an ejection fraction (EF) of 31%, completed the study. Home­based SBT was safe. After training, EF and 6MWT distance improved (EF: 31.3% ±7.3% vs 32.3% ±7.7%; P = 0.030; 6MWT: 449.9 ±122.7 m vs 468.3 ±121.9 m; P <0.001), and the apnea-hypopnea index decreased (5.6 [interquartile range (IQR), 2.1; 12.8] vs. 5.4 [IQR, 2.0; 10.8]; P = 0.043). CONCLUSIONS SBT improved physical capacity and systolic heart function; it also diminished sleep disturbances. The results support the benefits of SBT as a novel component of cardiorespiratory rehabilitation programs in patients with CHF.

Blood pressure changes in patients with chronic heart failure undergoing slow breathing training.

BACKGROUND: Slow breathing training (SBT) has been proposed as a new non-pharmacological treatment able to induce favorable effects in patients with chronic heart failure (CHF). However, no information is available regarding its effects on orthostatic blood pressure (BP) changes in these patients, an issue of practical relevance given the reported BP-lowering effect of SBT. The aim of this study is to evaluate the influence of SBT on BP and whether SBT induces orthostatic hypotension (OH) or changes in quality of life (QoL) in CHF patients. METHODS: The analysis was performed as part of an ongoing crossover open trial aimed at assessing the clinical effectiveness of SBT in treated patients with CHF. The patients underwent 10-12 weeks of SBT with the RESPeRATE device and 10-12 week follow-up under usual care. Patients were randomly divided into two groups: group I began with SBT, followed by usual care; group II began with usual care, followed by SBT. Patients undergoing SBT were asked to perform each day two separate 15 min sessions of device-guided SBT at a breathing frequency of 6 breaths/min. In all patients, before the enrollment and after each study phase, clinical data collection and BP measurements in sitting, supine and standing position were performed. OH was defined as a decrease of ≥ 20 mmHg in systolic blood pressure (SBP) or ≥ 10 mmHg in diastolic blood pressure (DBP) within 3 min of standing. QoL was assessed three times at the beginning, and after each phase of the study by the Minnesota Living with Heart Failure (MLHF) questionnaire. RESULTS: Forty patients (two equal groups) completed the study, with the following baseline characteristics: 32 males/eight females, age 63.3 ± 13.4 years, 25 with ischemic CHF, 37 in New York Heart Association class II and three in class III, left ventricular ejection fraction 30.8 ± 6.7%, mean BP 138.7 ± 16.5/83.1 ± 11.5 mmHg, 23 with arterial hypertension and four with a history of stroke. There were no significant differences between the groups in clinical characteristics, SBP and DBP at rest, while seated and before and after standing up. OH prevalence was low and did not change during the study (10% vs 10%). No significant difference in average SBP and DBP changes secondary to body position were found when comparing the two study phases. Decrease in MLHF score was observed in group I during SBT (p = 0.002), but not in group II. CONCLUSIONS: Our data indicate that SBT is safe, does not affect the prevalence of OH in CHF patients and shows a non-significant tendency to improve QoL. These results should be confirmed in a larger sample of patients to support the safety of SBT and its possible benefits as a novel component of cardiorespiratory rehabilitation programs in CHF.

Changes in 24 h ambulatory blood pressure and effects of angiotensin II receptor blockade during acute and prolonged high-altitude exposure: a randomized clinical trial.

AIM: Many hypertensive subjects travel to high altitudes, but little is known on ambulatory blood pressure (ABP) changes and antihypertensive drugs' efficacy under acute and prolonged exposure to hypobaric hypoxia. In particular, the efficacy of angiotensin receptor blockers in this condition is unknown. This may be clinically relevant considering that renin-angiotensin system activity changes at altitude. The HIGHCARE-HIMALAYA study assessed changes in 24 h ABP under acute and prolonged exposure to increasing altitude and blood pressure-lowering efficacy and safety of an angiotensin receptor blockade in this setting. METHODS AND RESULTS: Forty-seven healthy, normotensive lowlanders were randomized to telmisartan 80 mg or placebo in a double-blind, parallel group trial. Conventional and Ambulatory BPs were measured at baseline and on treatment: after 8 weeks at sea level, and under acute exposure to 3400 and 5400 m altitude, the latter upon arrival and after 12 days (Mt. Everest base camp). Blood samples were collected for plasma catecholamines, renin, angiotensin, and aldosterone. In both groups, exposure to increasing altitude was associated with: (i) significant progressive increases in conventional and 24 h blood pressure, persisting throughout the exposure to 5400 m; (ii) increased plasma noradrenaline and suppressed renin-angiotensin-aldosterone system. Telmisartan lowered 24 h ABP at the sea level and at 3400 m (between-group difference 4.0 mmHg, 95% CI: 2.2-9.5 mmHg), but not at 5400 m. CONCLUSION: Ambulatory blood pressure increases progressively with increasing altitude, remaining elevated after 3 weeks. An angiotensin receptor blockade maintains blood pressure-lowering efficacy at 3400 m but not at 5400 m.

[New non-pharmacological treatment methods in heart failure]. / Nowe metody niefarmakologicznego leczenia niewydolnosci serca.

The incidence of chronic heart failure (CHF) increases with the aging of the population and with the improvement in survival of patients with hypertension, coronary heart disease and diabetes, diseases which constitute the most common causes for the development of CHF. Despite the significant improvement in the treatment of patients with CHF, mortality in recent years has improved slightly. The primary treatment method for chronic heart failure is pharmacotherapy, but it has limitations. The existing data encourages to look for new treatment methods for CHF, replacing or enhancing traditional ones while constituting a low nuisance for patients. New non-pharmacological methods, including therapies based on the use of stem cells, molecular therapy, modern devices supporting the heart such as cardiac contractility modulation, spinal cord stimulation, carotid sinus nerve stimulation, cervical and intracardiac atrioventricular nodal vagal stimulation, implantable monitoring devices and wearable cardioverter-defibrillator or the treatment of comorbid diseases such as hypertension and sleep dis- orders could be of particular importance.

Effects of slow deep breathing at high altitude on oxygen saturation, pulmonary and systemic hemodynamics.

Slow deep breathing improves blood oxygenation (Sp(O2)) and affects hemodynamics in hypoxic patients. We investigated the ventilatory and hemodynamic effects of slow deep breathing in normal subjects at high altitude. We collected data in healthy lowlanders staying either at 4559 m for 2-3 days (Study A; N = 39) or at 5400 m for 12-16 days (Study B; N = 28). Study variables, including Sp(O2) and systemic and pulmonary arterial pressure, were assessed before, during and after 15 minutes of breathing at 6 breaths/min. At the end of slow breathing, an increase in Sp(O2) (Study A: from 80.2±7.7% to 89.5±8.2%; Study B: from 81.0±4.2% to 88.6±4.5; both p<0.001) and significant reductions in systemic and pulmonary arterial pressure occurred. This was associated with increased tidal volume and no changes in minute ventilation or pulmonary CO diffusion. Slow deep breathing improves ventilation efficiency for oxygen as shown by blood oxygenation increase, and it reduces systemic and pulmonary blood pressure at high altitude but does not change pulmonary gas diffusion.

Effects of beta-blockade on exercise performance at high altitude: a randomized, placebo-controlled trial comparing the efficacy of nebivolol versus carvedilol in healthy subjects.

AIMS: Exposure to high altitude (HA) hypoxia decreases exercise performance in healthy subjects. Although ß-blockers are known to affect exercise capacity in normoxia, no data are available comparing selective and nonselective ß-adrenergic blockade on exercise performance in healthy subjects acutely exposed to HA hypoxia. We compared the impact of nebivolol and carvedilol on exercise capacity in healthy subjects acutely exposed to HA hypobaric hypoxia. METHODS: In this double-blind, placebo-controlled trial, 27 healthy untrained sea-level (SL) residents (15 males, age 38.3 ± 12.8 years) were randomized to placebo (n = 9), carvedilol 25 mg b.i.d. (n = 9), or nebivolol 5 mg o.d. (n = 9). Primary endpoints were measures of exercise performance evaluated by cardiopulmonary exercise testing at sea level without treatment, and after at least 3 weeks of treatment, both at SL and shortly after arrival at HA (4559 m). RESULTS: HA hypoxia significantly decreased resting and peak oxygen saturation, peak workload, VO(2) , and heart rate (HR) (P < 0.01). Changes from SL (no treatment) differed among treatments: (1) peak VO(2) was better preserved with nebivolol (-22.5%) than with carvedilol (-37.6%) (P < 0.01); (2) peak HR decreased with carvedilol (-43.9 ± 11.9 beats/min) more than with nebivolol (-24.8 ± 13.6 beats/min) (P < 0.05); (3) peak minute ventilation (VE) decreased with carvedilol (-9.3%) and increased with nebivolol (+15.2%) (P= 0.053). Only peak VE changes independently predicted changes in peak VO(2) at multivariate analysis (R= 0.62, P < 0.01). CONCLUSIONS: Exercise performance is better preserved with nebivolol than with carvedilol under acute exposure to HA hypoxia in healthy subjects.

Effects of selective and nonselective beta-blockade on 24-h ambulatory blood pressure under hypobaric hypoxia at altitude.

BACKGROUND: Little is known about the effects of cardiovascular drugs at high altitude. OBJECTIVE: To assess 24-h blood pressure (BP) and heart rate (HR) during short-term altitude exposure in healthy normotensive persons treated with carvedilol or nebivolol. METHODS: Participants were randomized in double-blind to placebo, nebivolol 5 mg once daily or carvedilol 25 mg b.i.d. Tests were performed at sea level (baseline and after 2 weeks treatment) and on second to third day at altitude (Monte Rosa, 4559 m), still on treatment. Data collection included conventional BP, 24-h ambulatory BP monitoring (ABPM), oxygen saturation (SpO2), Lake Louise Score and adverse symptoms score. RESULTS: Twenty-four participants had complete data (36.4 ± 12.8 years, 14 men). Both beta-blockers reduced 24-h BP at sea level. At altitude 24-h BP increased in all groups, mainly due to increased night-time BP. Twenty-four-hour SBP at altitude was lower with carvedilol (116.4 ± 2.1 mmHg) than with placebo (125.8 ± 2.2 mmHg; P < 0.05) and intermediate with nebivolol (120.7 ± 2.1 mmHg; NS vs. others). Rate of nondipping increased at altitude and was lower with nebivolol than with placebo (33 vs. 71%; P = 0.065). Side effects score was higher with carvedilol than with placebo (P = 0.04), and intermediate with nebivolol. SpO2 at altitude was higher with placebo (86.1 ± 1.2%) than with nebivolol (81.7 ± 1.1%; P = 0.07) or carvedilol (81.1 ± 1.1%; P = 0.04). CONCLUSIONS: Both carvedilol and nebivolol partly counteract the increase in BP at altitude in healthy normotensive individuals but are associated with a lower SpO2. Carvedilol seems more potent in this regard, whereas nebivolol more effectively prevents the shift to a nondipping BP profile and is better tolerated.

Effects of cardiac resynchronization therapy on sleep apnea, quality of sleep and daytime sleepiness in patients with chronic heart failure.

BACKGROUND: Sleep-related breathing disorders are common in patients with chronic heart failure (CHF) and contribute to exacerbation of CHF. The effects of biventricular stimulation (CRT) seem to exceed the improvement of mechanical heart performance and are likely to affect other aspects of CHF pathophysiology. The aim of the study was to assess the influence of CRT on subjective and objective sleep features. MATERIAL AND METHODS: Twenty seven consecutive patients (aged 67.7 +/- 8.7 years, 23 men - 85%) with chronic heart failure (62.9% with ischaemic background and 37.1% of non-ischaemic etiology) in stable for at least 3 months NYHA class III - IV despite optimized pharmacotherapy, with left ventricular end-diastolic diameter (LVEDd) > 55 mm, left ventricular ejection fraction (LVEF) < or = 35% and wide QRS complex (> or = 120 ms) were appraised before and 12-16 weeks after CRT introduction clinically (including 6-minute walk test--6-MWT), echocardiographically and in polisomnography. The apnea-hypopnea index (AHI) and apnea indexes (AI) of central, obstructive and mixed types were calculated. The sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI), daytime sleepiness with the Epworth Sleepiness Scale (ESS). RESULTS: LVEF increased, 6-MWT distance rose. Left ventricular diameters and left ventricular end-systolic volume decreased. PQSI and ESS fell (9.3 +/- 4.2 vs 6.2 +/- 3.2, p < 0.001 and 8.4 +/- 4.1 vs 7.0 +/- 3.4, p < 0.001, respectively). AHI, obstructive AL and mixed AL did not alter but significant reduction of central AL was noted (9.6 +/- 13.0 vs 3.7 +/- 6.2, p = 0.023). CONCLUSIONS: CRT decreases central sleep apnea and improves quality of sleep and daytime sleepiness in patients with CHF.

Disappearance of isocapnic buffering period during increasing work rate exercise at high altitude.

BACKGROUND: At sea level, ventilation kinetics are characterized during a ramp exercise by three progressively steeper slopes, the first from the beginning of exercise to anaerobic threshold, the second from anaerobic threshold to respiratory compensation point, and the third from respiratory compensation point to peak exercise. In the second ventilation phase, body CO2 stores are used to buffer acidosis owing to lactate production; it has been suggested that this extra CO2 production drives the ventilation increase. At high altitude, ventilation increases owing to hypoxia. We hypothesize that ventilation increase reduces body CO2 stores affecting ventilation kinetics during exercise. DESIGN: In eight healthy participants, we studied the ventilation kinetics during an exercise performed at sea level and at high altitude (4559 m). METHODS: We used 30 W/2 min step incremental protocol both at sea level and high altitude. Tests were done on a cyclo-ergometer with breath-by-breath ventilation and inspiratory and expiratory gas measurements. We evaluated cardiopulmonary data at anaerobic threshold, respiratory compensation point, peak exercise and the VE/VCO2 slope. RESULTS: At high altitude: (a) peak VO2 decreased from 2595+/-705 to 1745+/-545 ml/min (P<0.001); (b) efficiency of ventilation decreased (VE/VCO2 slope from 25+/-2 to 38+/-4, P<0.0001); (c) at each exercise step end-tidal pressure change for CO2 was lower; and (d) the isocapnic buffering period disappeared in seven over eight participants and was significantly shortened in the remaining participant. CONCLUSION: Exercise performed at high altitude is characterized by two, instead of three, ventilation slopes.

Pulsatile but not steady component of blood pressure predicts cardiovascular events in coronary patients.

Although the differences between central and peripheral blood pressure (BP) values have been known for decades, the consequences of decision making based on peripheral rather than central BP have only recently been recognized. There are only a few studies assessing the relationship between intraaortic BP and cardiovascular risk. In addition, the relationship between central BP and the risk of cardiovascular events in a large group of coronary patients has not yet been evaluated. Therefore, the aim of the study was to determine the prognostic significance of central BP-derived indices in patients undergoing coronary angiography. Invasive central BPs were taken at baseline, and study end points were ascertained during over a 4.5-year follow-up in 1109 consecutive patients. The primary end point (cardiovascular death or myocardial infarction or stroke or cardiac arrest or heart transplantation or myocardial revascularization) occurred in 246 (22.2%) patients. Central pulsatility was the most powerful predictor of the primary end point (hazard ratio [HR] 1.30, 95% confidence interval [CI] 1.14 to 1.48). Central pulse pressure was also independently related to the primary end point (HR 1.25, 95% CI 1.09 to 1.43). Central mean BP as well as peripheral BP parameters were not independently related to the primary end point risk. Central pulsatility was also related to risk of cardiovascular death or myocardial infarction or stroke. The pulsatile component of BP is the most important factor related to the cardiovascular risk in coronary patients. It is more closely associated with cardiovascular risk than steady component of BP.