Heightened Dependence of Left-Heart Filling Pressures on Right-Heart Failure in Congenital Heart Disease

BackgroundPulmonary artery wedge pressure (PAWP) is often elevated in patients with right-sided congenital heart disease (CHD), raising the possibility of coexisting left-heart disease, but pressure-volume relationships in the left and right sides of the heart influence one another through interdependence, which may be amplified in patients with CHD.MethodsWe hypothesized that increases in PAWP in patients with CHD would be more strongly related to ventricular interdependence compared with patients who have isolated left-heart disease such as heart failure with preserved ejection fraction (HFpEF). Ventricular interdependence was assessed by the relationship between PAWP and right-atrial pressure (RAP), RAP/PAWP ratio, and the left-ventricular (LV) eccentricity index.ResultsPAWP was elevated (≥15 mm Hg) in 49% of patients with CHD (n = 449). There was a very strong correlation between RAP and PAWP in CHD (r = 0.81, P < 0.001) that greatly exceeded the respective correlation in HFpEF (n = 160; r = 0.58, P < 0.001; P < 0.001 between groups). RAP/PAWP ratio and LV eccentricity index were higher in CHD than HFpEF (1.26 ± 0.18 vs 1.05 ± 0.14, P = 0.007) and (0.80 ± 0.21 vs 0.59 ± 0.19, P < 0.001), respectively. RAP (but not PAWP) was an independent predictor of death/transplant (hazard ratio 1.86 per 5 mm Hg, 95% confidence interval, 1.39-2.45, P = 0.002).ConclusionsLeft-heart filling pressures are commonly elevated in right-sided CHD, but this is related predominantly to right-heart failure and enhanced ventricular interdependence rather than left-heart disease. These data provide new insight into the basis of abnormal left-heart hemodynamics in patients with CHD and reinforce the importance of therapeutic interventions targeted to the right heart.     

The use of a predicted CPAP equation improves CPAP titration success

Titration of continuous positive airway pressure (CPAP) is performed to determine the CPAP setting to prescribe for an individual patient. A prediction equation has been published that could be used to improve the success rate of CPAP titrations. The goals of this study were: (1) to test the hypothesis that the use of the prediction equation would achieve a higher rate of successful CPAP titrations; (2) to validate the equation as an accurate predictor of the prescribed CPAP setting and determine the factors that influence the accuracy of the prediction equation. A total of 224 patients underwent CPAP titration prior to using the equation, with a starting pressure of 5 cm H₂O. A total of 192 patients underwent CPAP titration using the equation-predicted CPAP level as the starting pressure (median starting pressure of 8 cm H₂O [interquartile range 7, 10 cm H₂O]). The percentage of successful studies, as defined by a 50% decrease in the apnea–hypopnea index (AHI) and a final AHI 10 cm H₂O, increased from 50% to 68% (p<0.001), while the number of patients who were prescribed a CPAP level that had not been tested decreased from 22% to 5% (p<0.001). The equation was not accurate in predicting the prescribed level of CPAP, with only 30.8% of the patients with a prescribed pressure 3 cm H₂O of the predicted pressure. Female gender was the only predictor of a prescribed pressure 3 cm H₂O from the predicted pressure (odds ratio 3.45, 95% confidence intervals 1.67, 7.13, p<0.001). A CPAP prediction equation modestly increases the rate of successful CPAP titrations by increasing the starting pressure of the titration. The equation does not accurately predict the prescribed CPAP level, reaffirming the need for a titration study to determine the optimal prescribed level in a given patient.     

Efficacy of nasal masks versus nasal pillows masks during continuous positive airway pressure titration for patients with obstructive sleep apnea

Purpose

Nasal masks are usually the first choice for CPAP therapy, but patients may experience side effects. There are limited data regarding the efficacy of nasal pillows masks during CPAP titration. This study aimed to compare the polysomnography outcomes during CPAP titration while comparing two types of masks (nasal and pillows) and to assess whether or not the patient characteristics differed between mask preferences.

Methods

In a sleep-disorders clinic, we prospectively analyzed all patients undergoing CPAP titration for three consecutive months. CPAP pressures were manually titrated. Anthropometric data (age, sex, body mass index, and neck and waist circumferences) and OSA severity were documented. Patients completed a self-administered questionnaire that measured nasal obstruction (NOSE scale). Before titration, both types of masks were presented to patients, and each of them chose the one they preferred.

Results

Of 157 patients, 55% (n = 86) used nasal masks, and 45% (n = 71) used nasal pillows masks. There was no difference according to mask type chosen by age, sex, body mass index, neck and waist circumferences, and NOSE scale. Polysomnography outcomes were similar between the mask groups. The mean CPAP level was 9.4 ± 1.8 cm H₂O for nasal masks and 9.1 ± 2.0 cm H₂O for nasal pillows (p = 0.61). Residual apnea-hypopnea index was 3.0 ± 2.8 events/h for nasal mask and 3.5 ± 4.1 events/h for pillow mask (p = 0.28). Baseline AHI, body mass index, neck and waist circumferences, and residual AHI were independent predictors of a higher CPAP pressure for both groups (p < 0.0001).

Conclusions

Nasal pillows masks seem to be as effective as nasal masks and may be considered to be an initial choice for CPAP titration.

     

持续气道正压通气对急性心源性肺水肿犬呼吸及循环功能的影响

目的研究持续气道正压(CPAP)通气对急性心源性肺水肿(ACPE)犬呼吸及循环功能的影响。方法分别监测10条犬健康状态及ACPE发生后自主呼吸、5cmH2O(1cmH2O=0.098kPa)、10cmH2O、15cmH2OCPAP时的胸腔负压(Pt)、中心静脉压(CVP)、心输出量(CO)、平均动脉压(BPm)、肺动脉楔压(PAWP)。结果与健康状态相比,ACPE犬呼吸增强、增快,Pt由-(4.90±0.09)cmH2O上升至-(10.90±0.75)cmH2O,CVP由(10.1±0.4)mmHg下降至(8.0±0.7)mmHg,CO由(1.52±0.13)L/min下降至(0.85±0.09)L/min,PAWP升高(P均<0.05)。CVP与Pt变化呈正相关(r=0.78,P<0.01)。5及10cmH2OCPAP时Pt值恢复至-(6.53±0.11)cmH2O和-(5.14±0.25)cmH2O,呼吸形式基本恢复正常,CVP升至(11.6±0.7)mmHg和(14.2±0.2)mmHg,CO增加至(1.45±0.11)L/min和(1.24±0.11)L/min,其中5cmH2OCPAP组PAWP下降(P均<0.05)。15cmH2OCPAP时,呼吸浅快,Pt为-(0.82±0.37)cmH2O,CO为(0.82±0.07)L/min,其他血流动力学指标皆恶化(P均<0.05)。结论犬ACPE发生时,呼吸运动显著增强,Pt升高,并导致CVP和CO的下降;适当CPAP通过改善呼吸功能,调节Pt改善ACPE犬的心功能。     

Hemodynamic effects of bilevel nasal positive airway pressure ventilation in patients with heart failure

AIMS: Benefits of nasal continuous positive airway pressure (CPAP) in patients presenting with chronic heart failure (CHF) are controversial. The purpose of this study was to compare the hemodynamic effects of CPAP and bilevel positive airway pressure (BiPAP) in patients with or without CHF. METHODS AND RESULTS: Twenty patients with CHF and 7 with normal left ventricular function underwent cardiac catheterization. Measurements were made before and after three 20-min periods of BiPAP: expiratory positive airway pressure (EPAP) = 8 cm H2O and inspiratory positive airway pressure (IPAP) = 12 cm H2O, EPAP = 10 cm H2O and IPAP = 15 cm H2O, and CPAP = EPAP = IPAP = 10 cm H2O administered in random order. Positive pressure ventilation decreased cardiac output (CO) and stroke volume. No change was observed in either pulmonary or systemic arterial pressure. There was no difference in the hemodynamic effects of the three ventilation settings. Only mean pulmonary wedge pressure (MPWP) and heart rate were lower with CPAP than with BiPAP. CO decreased only in patients with low MPWP (相似文献   

Cardiopulmonary effects of one-lung ventilation in supine patients

The cardiopulmonary effects of one-lung ventilation (OLV), with continuous positive airway pressure (CPAP, 5 cm H₂O) to the nonventilated lung, were compared to the effects of two-lung ventilation (TLV) in 12 supine patients undergoing coronary artery bypass grafting (CABG). Monitoring was performed with electrocardiography (ECG), arterial, and pulmonary artery catheters. Measurements of cardiac index (CO, heart rate (HR), systemic (MAP) and pulmonary artery pressures (PAP), pulmonary artery occlusion pressure (PAOP), mixed venous oxygen saturation (SvO₂), and arterial blood for pH, PaO₂, PaCO₂ and HCO₃- were performed with stable maintenance of anesthesia during both one- and two-lung ventilation. Mean values for CI, HR, MAP, MPAP, PVR, and S_vO₂ demonstrated no significant changes between OLV and TLV; systemic vascular resistance (SVR) and pulmonary artery occlusion pressure (PAOP) were statistically (P < 0.05) different, but of minor clinical significance. The data suggest that OLV, accompanied by CPAP (5 cm H₂0) to the nonventilated lung, produces minimal changes in cardiopulmonary measurements in supine patients.     

Automatic CPAP Performance in Patients with Sleep Apnea Plus COPD

Abstract

Background: Automatic CPAP devices have demonstrated good results in obtaining optimal fixed CPAP pressure to eliminate respiratory events in patients with sleep apnea-hypopnea syndrome (SAHS). However, automatic CPAP has not been fully studied in patients with COPD plus SAHS. Objectives: To analyse the performance of an automatic CPAP in severe COPD patients compared with SAHS patients with no associated co-morbidity. Methods: We compared 10 consecutive patients with SAHS and no associated co-morbidity and 10 patients with SAHS plus severe COPD who required CPAP titration. Automatic CPAP performance was studied during full-night PSG. Inadequate pressure increase periods, absence of pressure increases in reaction to respiratory events, air leak periods, and pressure behaviour in the face of erratic breathing periods were analysed. Results: The SAHS patients without co-morbidities vs. SAHS plus COPD patients presented: mean sleep efficiency, 80.2 (11.5)% vs. 76.5 (12.1)%; residual AHI, 6.3 (5.2) vs. 5.1 (7.7); residual CT90, 1 (3)% vs. 14 (1)%. The device´s performance demonstrates a mean of 1.2 (1.5) vs. 1.3 (1.2) periods of inadequate pressure increases; absence of pressure increases in reaction to respiratory events, 4.1 (5.4) vs. 0.6 (0.7) times; periods of air leaks, 1.3 (3.8) vs. 13.9 (11.7); mean optimal pressure, 9.1 (1.4) vs. 9.0 (1.9) cm H₂O. Conclusion: Titration with automatic CPAP could be as effective in patients with SAHS plus severe COPD as in patients with SAHS without COPD. However, the presence of more leakages must be taken into account.     

Hemodynamic Effects of Pulmonary Arterial Hypertension-Specific Therapy in Patients With Heart Failure With Preserved Ejection Fraction and With Combined Post- and Precapillay Pulmonary Hypertension

BackgroundDrugs approved for pulmonary arterial hypertension have been considered for patients with heart failure with preserved ejection fraction and combined post- and precapillary pulmonary hypertension (Cpc-PH). We aimed to study changes in cardiac volumes, cardiac load and left ventricular (LV) filling pressures in patients with heart failure with preserved ejection fraction and Cpc-PH in response to pulmonary arterial hypertension-specific treatment.Methods and ResultsIn this prospective study, 23 patients with heart failure with preserved ejection fraction and Cpc-PH underwent right-heart catheterization, including acute provocation testing (fluid loading and inhaled nitric oxide) and cardiac MRI at baseline. Right-heart catheterization and cardiac MRI were repeated after 4 months of treatment. At baseline, acutely increasing preload by fluid loading resulted in a significant increase in pulmonary arterial wedge pressure (PAWP), whereas reducing right ventricular (RV) afterload and increasing LV distensability by acute administration of inhaled nitric oxide had no effect on PAWP. After 4 months of treatment, we observed a significant reduction in RV and LV afterload and increased RV and LV stroke volume, but PAWP significantly increased.ConclusionsIn patients with heart failure with preserved ejection fraction and Cpc-PH, 4 months of pulmonary arterial hypertension-specific treatment increased RV and LV stroke volume at the expense of increased PAWP. This increase in PAWP was similarly observed acutely after fluid loading.     

Adaptive pressure support servo-ventilation: a novel treatment for Cheyne-Stokes respiration in heart failure

Adaptive servo-ventilation (ASV) is a novel method of ventilatory support designed for Cheyne-Stokes respiration (CSR) in heart failure. The aim of our study was to compare the effect of one night of ASV on sleep and breathing with the effect of other treatments. Fourteen subjects with stable cardiac failure and receiving optimal medical treatment were tested untreated and on four treatment nights in random order: nasal oxygen (2 L/min), continuous positive airway pressure (CPAP) (mean 9.25 cm H(2)O), bilevel (mean 13.5/5.2 cm H(2)O), or ASV largely at the default settings (mean pressure 7 to 9 cm H(2)O) during polysomnography. Thermistor apnea + hypopnea index (AHI) declined from 44.5 +/- 3.4/h (SEM) untreated to 28.2 +/- 3.4/h oxygen and 26.8 +/- 4.6/h CPAP (both p < 0.001 versus control), 14.8 +/- 2.3/h bilevel, and 6.3 +/- 0.9/h ASV (p < 0.001 versus bilevel). Effort band AHI behaved similarly. Arousal index decreased from 65.1 +/- 3.9/h untreated to 29.8 +/- 2.8/h oxygen and 29.9 +/- 3.2/h CPAP, to 16.0 +/- 1.3/h bilevel and 14.7 +/- 1.8/h ASV (p < 0.01 versus all except bilevel). There were large increases in slow-wave and rapid eye movement (REM) sleep with ASV but not with oxygen or CPAP. All subjects preferred ASV to CPAP. One night ASV suppresses central sleep apnea and/or CSR (CSA/CSR) in heart failure and improves sleep quality better than CPAP or 2 L/min oxygen.     

Cheyne-Stokes respiration in congestive heart failure: continuous positive airway pressure of 5-8 cm H2O for 1 year in five cases

Five adult patients with congestive heart failure (CHF) due to dilated cardiomyopathy complicated by Cheyne-Stokes respiration/central sleep apnea (CSR/CSA) were treated with continuous positive airway pressure (CPAP) with an initial pressure of 5 cm H2O. Four patients were followed up for 12 months with CPAP of 5 cm H2O. The rest, a 93-year-old patient, was followed up for 30 months, and the CPAP was reset at 8 cm H2O due to worsened cardiac function after 6 months and it was reset at 6 cm H2O due to dryness of the nose after 23 months. For all the patients with nightly CPAP use for 6.0+/-1.4 h per day for a year, frequency of CSR/CSA was significantly reduced after 3 and 12 months with CPAP (p<0.05). Moreover, their symptoms, cardiac function and sleep quality were significantly improved after 3 months (p<0.05), and were maintained above the pre-CPAP levels after 12 months, except for the oldest patient whose cardiac function tended to deteriorate. The results suggest that CSR/CSA in CHF can be treated with CPAP set at a lower pressure than the conventional method, and that CPAP at 5-8 cm H2O is often effective in eliminating CSR/CSA, improving sleep quality, and presumably maintaining cardiac function.     

Right Atrial/Pulmonary Arterial Wedge Pressure Ratio in Primary and Mixed Constrictive Pericarditis

BackgroundCardiac filling pressures may be elevated due to abnormalities in the myocardium, heightened pericardial restraint, or both. The authors hypothesized that the relative contributions due to myocardium and pericardium could be estimated by the ratio between right atrial pressure and pulmonary arterial wedge pressure (RAP/PAWP), which would enable better discrimination of the extent of myocardial disease in patients with constrictive pericarditis (CP).ObjectivesThis study investigated the relationships between RAP/PAWP and the pericardial thickness as well as echocardiographic parameters of myocardial function and assessed the prognostic implications of RAP/PAWP for long-term mortality in primary and mixed CP patients who underwent pericardiectomy.MethodsA total of 113 surgically confirmed CP patients who underwent echocardiography and cardiac catheterization within 7 days of each other between 2005 and 2013 were included in the study. The patients were classified into a high RAP/PAWP group (≥0.77; n = 56) or a low RAP/PAWP group (<0.77; n = 57) according to the median RAP/PAWP value. The primary outcome was prognostic implication of RAP/PAWP on long-term mortality and assessment of the relationship between RAP/PAWP and Doppler echocardiographic parameters in primary and mixed CP. In addition, the relationship between RAP/PAWP and the pericardial thickness was assessed.ResultsRAP/PAWP was directly correlated with pericardial thickness (regression coefficient [β] = 8.34; p < 0.001). RAP/PAWP had a significant direct correlation with early diastolic velocity of medial mitral annulus (eʹ) (β = 10.69; p < 0.001) and inverse relationship with early transmitral diastolic velocity (E) (β = −105.15; p < 0.001), resulting in an inverse relationship with the ratio of E/eʹ (β = −23.53; p < 0.001). Patients with high RAP/PAWP ratio had a better survival rate compared with those with low RAP/PAWP ratio (p = 0.01). Its prognostic value was significant in primary CP (p = 0.03) but not in mixed CP with concomitant myocardial disease (p = 0.89).ConclusionsThe RAP/PAWP ratio can reflect the degree of pericardial restraint versus restrictive myocardium and was associated with the long-term survival after pericardiectomy.     

Effects of changes in lung volume on oscillatory flow rate during high-frequency chest wall oscillation

BACKGROUND:

The effectiveness of high-frequency chest wall oscillation (HFCWO) in mucolysis and mucous clearance is thought to be dependant on oscillatory flow rate (Fosc). Therefore, increasing Fosc during HFCWO may have a clinical benefit.

OBJECTIVES:

To examine effects of continuous positive airway pressure (CPAP) on Fosc at two oscillation frequencies in healthy subjects and patients with airway obstruction.

METHODS:

Five healthy subjects and six patients with airway obstruction underwent 12 randomized trials of HFCWO (CPAP levels of 0 cm H₂O, 2 cm H₂O, 4 cm H₂O, 6 cm H₂O, 8 cm H₂O and 10 cm H₂O at frequencies of 10 Hz and 15 Hz) within a body plethysmograph, allowing measurements of changes in lung volume. Fosc was measured by reverse plethysmography using a 20 L isothermic chamber near the mouth. At the end of each randomized trial, an inspiratory capacity manoeuvre was used to determine end-expiratory lung volume (EELV).

RESULTS:

EELV increased significantly (P<0.05) with each level of CPAP regardless of oscillation frequency. Fosc also significantly increased with CPAP (P<0.05) and it was correlated with EELV (r=0.7935, P<0.05) in obstructed patients but not in healthy subjects (r=0.125, P=0.343). There were no significant differences in perceived comfort across the levels of CPAP.

CONCLUSIONS:

Significant increases in Fosc with CPAP-induced increases in lung volume were observed, suggesting that CPAP may be useful as a therapeutic adjunct in patients who have obstructive airway disease and who require HFCWO.     

Short term effect of continuous positive airway pressure on muscle sympathetic nerve activity in patients with chronic heart failure

OBJECTIVE—To test the hypothesis that the short term application of continuous positive airways pressure (CPAP) increases muscle sympathetic nerve activity in patients with congestive heart failure.
SETTING—University hospital and tertiary referral centre.
PATIENTS—10 patients with congestive heart failure (New York Heart Association functional class III; mean (SEM) left ventricular ejection fraction 22 (1)%) and 10 healthy subjects matched for age, sex, and weight.
MAIN OUTCOME MEASUREMENTS—Muscle sympathetic nerve activity, assessed by microneurography of the peroneal nerve, blood pressure, heart rate, minute ventilation, transcutaneous oxygen saturation, and end tidal PCO₂ were measured during normal breathing, mask breathing, and CPAP at 5 and 10 cm H₂O.
RESULTS—CPAP induced an increase in muscle sympathetic nerve activity and blood pressure in both the patients and the control subjects. In the patients, sympathetic nerve activity increased from 43 (14) bursts/min during mask breathing to 47 (13) bursts/min at CPAP 10 cm H₂0 (p = 0.03); mean blood pressure increased from 80 (3) mm Hg to 86 (4) mm Hg (p < 0.001). Oxygen saturation improved during CPAP in the patients, from 95.7 (0.6)% to 96.6 (0.7)% (p = 0.004) and remained stable in the control group. There was no effect of CPAP on minute ventilation or heart rate.
CONCLUSIONS—In patients with congestive heart failure, short term CPAP elicits sympathetic activation, probably because of unloading of the aortic or cardiopulmonary baroreceptors.


     

Inotrope Use and Outcomes Among Patients Hospitalized for Heart Failure: Impact of Systolic Blood Pressure,Cardiac Index,and Etiology

BackgroundInotropes are widely used in hospitalized systolic heart failure (HF) patients, especially those with low systolic blood pressure (SBP) or cardiac index. In addition, inotropes are considered to be harmful in nonischemic HF.Methods and ResultsWe examined the association of in-hospital inotrope use with (1) major events (death, ventricular assist device, or heart transplant) and (2) study days alive and out of hospital during the first 6 months in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness, which excluded patients with immediate need for inotropic therapy. Predefined subgroups of interest were baseline SBP <100 versus ≥100 mm Hg, cardiac index <1.8 vs ≥1.8 L min⁻¹ m⁻², and ischemic versus nonischemic HF etiology. Inotropes were frequently used in both the <100 mm Hg (88/165 [53.3%]) and the ≥100 mm Hg (106/262 [40.5%]) SBP subgroups and were associated with higher risk for major events in both subgroups (adjusted hazard ratio [HR] 2.85, 95% confidence interval [CI] 1.59–5.12 [P < .001]; and HR 1.86, 95% CI 1.02–3.37 [P = .042]; respectively). Risk with inotropes was more pronounced among those with cardiac index ≥1.8 L min⁻¹ m⁻² (n = 114; HR 4.65, 95% CI 1.98–10.9; P < .001) vs <1.8 L min⁻¹ m⁻² (n = 82; HR 1.48, 95% CI 0.61–3.58; P = .39). Event rates were higher with inotropes in both ischemic (n = 215; HR 2.64, 95% CI 1.49–4.68; P = .001) and nonischemic (n = 216; HR 2.19, 95% CI 1.18–4.07; P = .012) patients. Across all subgroups, patients who received inotropes spent fewer study days alive and out of hospital.ConclusionsIn the absence of cardiogenic shock or end-organ hypoperfusion, inotrope use during hospitalization for HF was associated with unfavorable 6-month outcomes, regardless of admission SBP, cardiac index, or HF etiology.     

Prognostic Impact of Combined Late Gadolinium Enhancement on Cardiovascular Magnetic Resonance and Peak Oxygen Consumption in Ambulatory Patients With Nonischemic Dilated Cardiomyopathy

BackgroundPeak oxygen consumption (peak VO₂) and late gadolinium enhancement (LGE) on cardiovascular magnetic resonance (CMR) are prognostic in heart failure. We investigated whether LGE-CMR and peak VO₂ combined had additive value in risk stratifying patients with nonischemic dilated cardiomyopathy (DCM).Methods and ResultsFifty-seven DCM patients underwent CMR and cardiopulmonary exercise testing. Cardiac events were cardiac death, hospitalization for decompensated heart failure, or lethal arrhythmia. Twenty-five (44%) were LGE-positive. The median peak VO₂ was 18.5 mL·kg^-1·min^-1. On multivariate analysis, positive LGE (P = .048) and peak VO₂ (P = .003) were independent cardiac event predictors. Cardiac event risk was significantly higher with positive LGE and peak VO₂ < 18.5 mL·kg^-1·min^-1 than with negative LGE and peak VO₂ ≥ 18.5 mL·kg^-1·min^-1 (hazard ratio 12.5; 95% CI 1.57–100; P = .017). In 3 patient groups (group A: no LGE, peak VO₂ ≥ 18.5 mL·kg^-1·min^-1, n = 18; group B: positive LGE or peak VO₂ < 18.5 mL·kg^-1·min^-1, n = 24; group C: positive LGE and peak VO₂ < 18.5 mL·kg^-1·min^-1, n = 15) during follow-up (71 ± 32 months), group C had higher cardiac event rates than the others.ConclusionsCombined assessment of LGE-CMR and peak VO₂ provides additive prognostic information in ambulatory DCM.     

The Differential Impact of the Left Atrial Pressure Components on Pulmonary Arterial Compliance–Resistance Relationship in Heart Failure

BackgroundAn increase in the pulmonary capillary wedge pressure (PAWP) has been shown to impact on the inherent relationship between the pulmonary arterial compliance (PAC) and pulmonary vascular resistance (PVR), thus augmenting the pulsatile relative to the resistive load of the right ventricle. However, the PAWP comprises the integration of both the steady and the pulsatile pressure components. We sought to address the differential impact of the these distinct PAWP components on the PAC–PVR relationship in a cohort of patients with heart failure. Methods and ResultsThe study population consisted of 192 patients with hemodynamic findings diagnostic for heart failure. Off-line analysis was performed using the MATLAB software. The steady and pulsatile PAWP components were calculated as mid-A pressure and mean pressure during the V-wave oscillation, respectively. The PAC and PVR were hyperbolically and inversely associated and the subgroup of patients with PAWP above the median (>18 mm Hg) displayed a significant left and downward shift of the curve fit (P < .001). The shift in the PAC–PVR fit between patients with higher versus low steady PAWP was not significant (P = .43). In contrast, there was a significant downward and leftward shift of the PVR–PAC curve fit for the subgroup with a higher pulsatile PAWP (P < .001). Furthermore, only the pulsatile PAWP was significantly associated with the time-constant of the pulmonary circulation, assessed as the PAC × PVR product (P < .001).ConclusionsIn patients with heart failure, the pulsatile rather than the steady PAWP component stands for the previously documented shift of the PAC–PVR relationship occurring at an elevated PAWP.     

The role of high-frequency jet ventilation in the treatment of Cheyne-Stokes respiration in patients with chronic heart failure

BACKGROUND: Cheyne-Stokes respiration with central sleep apnea (CSR-CSA) is common in patients with severe cardiac failure. Various modes of positive airway pressure have been suggested as treatments.The authors hypothesized that high frequency jet ventilation (HFJV) can improve central sleep apnea in patients with chronic heart failure. METHODS: Eleven subjects with stable, optimally treated chronic heart failure and Cheyne-Stokes respiration were tested untreated and on four treatment nights in random order: nasal oxygen (4 L/min), continuous positive airway pressure (CPAP) (mean 9.3 cm H(2)O), bilevel positive airway pressure (BiPAP)(mean 12.0/5.3 cm H(2)O), or HFJV(60 approximately 80 breaths per minute) during polysomnography (EMBLA, Flaga, Reykjavik, Iceland). RESULTS: The apnea-hypopnea index (AHI) declined from 30.9 +/- 8.3/h in untreated night to 23.6 +/- 6.6/h oxygen night and 18.5 +/- 5.0/h CPAP, 14.3 +/- 3.9/h BiPAP, and 20.1 +/- 4.1/h HFJV (all P < 0.001 versus control). There was no significant difference between the AHI of HFJV and that of CPAP (P = 0.541). Arousal index decreased from 31.4+/-13.2/h untreated to 25.0 +/- 7.1/h oxygen and 13.6 +/- 4.7/h CPAP, to 13.7 +/- 4.9/h BiPAP and 14.4 +/- 4.7/h HFJV. HFJV had the similar effect to the other therapeutic groups in arousal index (P > 0.05). There were large increases in slow-wave and rapid eye movement (REM) sleep with HFJV. All subjects preferred HFJV to CPAP. CONCLUSIONS: One night of therapy with HFJV improved nocturnal breathing pattern and sleep quality in patients with Cheyne-Stokes respiration in chronic heart failure. HFJV therapy for sleep and breathing were the same as those during a nasal CPAP night. A long-term study of the effect of HFJV on cardiovascular function is needed.     

Effects of dynamic bilevel positive airway pressure support on central sleep apnea in men with heart failure

BACKGROUND: Treatment with continuous positive airway pressure (CPAP) improves cardiac function in chronic heart failure (CHF) patients with central sleep apnea (CSA)-Cheyne-Stokes respiration (CSR) by stabilizing ventilation, but frequently central apneas and hypopneas persist. Our objective was to test the hypothesis that flow-targeted dynamic bilevel positive airway pressure (BPAP) support (BiPAP autoSV; Respironics; Murrysville, PA) effectively suppresses CSR-CSA in CHF patients. METHODS: We studied 14 CHF patients with CSR-CSA (and residual CSA on positive airway pressure therapy) during 3 consecutive nights: (1) diagnostic polysomnography, (2) CPAP (n=10) or BPAP (n=4) titration, and (3) dynamic flow-targeted dynamic BPAP support with an expiratory positive airway pressure (EPAP) set to suppress obstructive respiratory events, and an inspiratory positive airway pressure (IPAP) dynamically ranging between 0 and 15 cm H2O above the EPAP. RESULTS: CPAP or BPAP significantly reduced the apnea-hypopnea index (AHI) [mean+/-SD, 46+/-4 events/h to 22+/-4 events/h; p=0.001] compared to the first night without treatment. Flow-targeted dynamic BPAP support (mean EPAP, 6.5+/-1.7 cm H2O; maximal IPAP, 21.9+/-2.1 cm H2O) further reduced the AHI to 4+/-1/h of sleep compared to the untreated (p<0.001) and CPAP or BPAP night (p=0.002). After the first night of flow-targeted dynamic BPAP support, patients rated on an analog scale (range, 0 to 10) the treatment as comfortable (6.9+/-0.6), and the sleep quality as improved compared to previous nights (7.4+/-0.6). CONCLUSION: Flow-targeted dynamic BPAP support effectively suppresses CSR-CSA in patients with CHF and is well tolerated.     

Effect of nasal continuous positive airway pressure on cardiac output and oxygen delivery in patients with congestive heart failure.

We studied the acute hemodynamic effects of increasing nasal continuous positive airway pressure (CPAP) in 13 patients with acute decompensation of congestive heart failure. Heart rate, respiratory rate, pulmonary capillary wedge pressure, right atrial pressure, systemic blood pressure, and thermodilution cardiac outputs were measured at baseline, during, and after application of nasal CPAP at increasing pressures of 5, 10, and 15 cm H2O. Cardiac index, stroke volume, and oxygen delivery were calculated. Based on a significant change in cardiac output greater than or equal to 400 ml, seven patients were classified as responders, whereas six patients were considered to be nonresponders. In responders, significant increases were noted in cardiac index (2.5 +/- 0.7 to 2.9 +/- 0.9 L/min/m2), stroke volume (49 +/- 15 to 57 +/- 16 ml), and oxygen delivery (10.3 +/- 5.1 to 12.3 +/- 6.0 ml/min/kg) without a change in pulmonary capillary wedge pressure. In contrast, the nonresponders showed no significant change in any of the hemodynamic parameters. Improvement in cardiac output could not be predicted by any of the baseline hemodynamic or clinical variables, nor was it related to random variations since all variables returned to baseline after cessation of CPAP. Increase in stroke volume without a change in pulmonary capillary wedge pressure (preload) suggests either improved inotropic function of the left ventricle or reduced left ventricular afterload with CPAP. Thus, CPAP may offer a new noninvasive adjunct to improving left ventricular function and augmenting cardiac performance in a subset of patients with congestive heart failure.     

Determinants and Prognostic Implications of Left-Heart Filling Pressures in Tetralogy of Fallot

BackgroundElevated pulmonary artery wedge pressure (PAWP) is the hallmark of left-heart failure and is responsible for heart failure symptoms and mortality. Although PAWP typically correlates with right atrial pressure (RAP), it is primarily dependent on left-heart myocardial properties and volume status. As right-heart disease can occur in the absence of left-heart disease in patients with tetralogy of Fallot (TOF), we hypothesized that RAP was the primary determinant of PAWP in this population.MethodsA cohort study of adults with TOF that underwent right-heart catheterization at Mayo Clinic Rochester (1990 to 2017) to determine the relationship among RAP, PAWP, and mortality.ResultsAmong 213 patients (male 105; age 37 ± 14 years), the mean PAWP was 14 ± 5 mm Hg, and RAP was 11 ± 5 mm Hg. RAP was the strongest predictor of PAWP (β = 0.68, standard error = 0.06, P < 0.001), independent of left-heart disease and atherosclerotic cardiovascular risk factors. The patients with high PAWP also had normal tissue Doppler velocities, suggesting normal left-ventricular myocardial properties. PAWP was an independent predictor of death/transplant (hazard ration [HR] 1.11, 95% confidence interval [CI], 1.03-1.20, P = 0.004). However, when RAP was incorporated into the regression model, RAP (and not PAWP) became the independent predictor of outcomes (HR 1.14, 95% CI, 1.06-1.22, P = 0.001).ConclusionsThe current study showed that RAP was the primary determinant of PAWP and accounts, to some extent, for the mortality in patients with TOF and high PAWP. The data provide new insight in the pathophysiology of disease progression for symptomatic patients with TOF.