Sleep-disordered breathing and lung function abnormalities in adults with congenital heart disease.

PURPOSE: Advances in treatment enables most patients with congenital heart diseases (CHD) to survive into adulthood, implying the need to address comorbid conditions in this growing cohort of patients. The aim of this study was to evaluate the prevalence of sleep-disordered breathing (SDB) and lung function abnormalities in patients with adult congenital heart disease (ACHD). METHODS: Patients with ACHD underwent level 3 sleep testing (Embletta MPR polygraphy) and pulmonary function testing. Results were stratified by the underlying haemodynamic ACHD lesion group. RESULTS: Patients with ACHD (n = 100) were middle-aged (42.3 ± 14.6 years), 54% male and slightly overweight (BMI 25.9 ± 5.5 kg/m2). Polygraphy revealed a prevalence of sleep apnoea of 39% with 15% of patients presenting with predominantly obstructive apnoeic episodes, while 23% of patients presenting primarily with central sleep apnoea. The distribution of mild, moderate, and severe sleep apnoea in the total study population was 26%, 7% and 6%, respectively. Comparison of apnoea-hypopnoea index, presence of sleep apnoea, and apnoea severity did not offer significant differences between the four ACHD lesion groups (p = 0.29, p = 0.41 and p = 0.18, respectively). Pulmonary function testing revealed obstructive lung disease in 19 of 100 patients. Concomitant chronic obstructive pulmonary disease and obstructive sleep apnoea were diagnosed in 3% of patients and were associated with profound nocturnal desaturation. CONCLUSION: The findings suggest a mild propensity amongst patients with ACHD to develop SDB that seems to be unaffected by the specific underlying congenital lesion.

The effect of normovolemic modified ultrafiltration on inflammatory mediators, endotoxins, terminal complement complexes and clinical outcome in high-risk cardiac surgery patients.

OBJECTIVE: The clinical benefit of normovolemic modified ultrafiltration (N-MUF) after cardiac surgery is still debated. As we have shown in a previous publication, there is a significant improvement in platelet function, so we were interested in whether ultrafiltration can reduce plasma levels of endotoxins, terminal complement complexes and cytokines after cardiopulmonary bypass (CPB) in adults with increased risk profiles. METHODS: In this single-center, prospective, randomized trial, fifty high-risk patients (mean logistic EuroSCORE II: 17.5%) who underwent cardiac surgery were randomized. After CPB, Group 1 (n = 25) served as the control and in, Group 2 (n= 25), an N-MUF of 3000 ml was performed, using a BC140plus filter after weaning from CPB. Blood samples were taken after the induction of anesthesia, before CPB, before CPB weaning, 30 minutes after CPB and at 6, 24 and 48 hours postoperatively. Primary outcomes were plasma levels of lipopolysaccharide-binding protein (LBP), terminal complement complex (C5b9) and cytokines (IL-6, IL-10, IL-1beta, TNF-α). Secondary outcomes focused on differences in the clinical outcome. RESULTS: A significant reduction in LBP concentration (preoperatively: 23.8±8.4 pg/ml, postoperatively: 14.2±12.9 pg/ml) and C5b9 (preoperatively: 4.18±2.6 pg/ml, postoperatively: 3.05±2.39 pg/ml) were detected 6 hours after N-MUF. In the N-MUF group, significantly lower concentrations of lactate could be detected in the early postoperative period. Furthermore, postoperative chest tube blood loss was significantly lower in the N-MUF group at 24 and 48 hours. CONCLUSIONS: N-MUF leads to a significant reduction of lipopolysaccharide-binding protein and terminal complement complex and was associated with reduced blood loss and postoperative lactate concentrations shortly after surgery.

Leukocyte depletion during cardiac surgery with extracorporeal circulation in high risk patients.

BACKGROUND: Cardiopulmonary bypass is associated with systemic inflammation that may contribute to increased perioperative mortality. Depletion of circulating leukocytes may reduce the inflammatory response. We studied the effect of a leukocyte depleting filter on leukocyte activation during cardiopulmonary bypass in high risk patients. METHODS: Fifty patients undergoing coronary artery bypass grafting with a preoperative high risk were randomly placed in an arterial line leukocyte filter group (n = 25) with a leukocyte depleting filter. Blood sampling took place from the arterial line to analyze polymorphnuclear elastase and myeloperoxidase at six time points, including: A) before the induction of anesthesia, B) before the induction of the cardiopulmonary bypass C) 1 min after the release of the aorta clamp, D) the end of the operation, E) 1 h postoperative, and F) 24 h postoperative. RESULTS: Levels of polymorphonuclear elastase, (PMNE), and myeloperoxidase (MPO) were found to be higher after the release of the aortic cross clamp in the leukocyte filter group; these levels remained elevated until 24 hours after surgery and were high in comparison to preoperative baseline levels. The differences in PMNE between both groups at time points C and D (p < 0.005) and E (p < 0.05) were statistically significant. The serum levels of the S-100B and neuron specific enolase (NSE) were found to be elevated between time points C and E in both groups without statistical significance. The in-hospital mortality was 16% (4 patients) in leukocyte filter group and 4% in control group (1 patient). CONCLUSIONS: Interestingly, the activation of neutrophils was more pronounced in the LF group. The use of a leucocyte depleting filter was not advantageous for this patient cohort for clinical or biomedical endpoints.

Impact of valve calcification on systolic and diastolic valvular function--an in vitro model.

AIM: Despite continuous development of anticalcification treatment for bioprosthetic valves, calcification remains one major cause of structural failure. The aim of this study is to investigate changes in hemodynamic performance and leaflet kinematics in progressively calcified pericardial and porcine aortic valve prostheses. METHODS: Five pericardial (Edwards Perimount Magna) and 5 porcine (Medtronic Mosaic Ultra) aortic valve prostheses (Ø23 mm) were exposed to a high concentration Calcium-phosphate fluid in an in vitro pulse duplicator (300 cycles/minute) for 6 weeks. The prostheses were removed weekly and tested in an artificial circulation system (70 beats/min, Cardiac Output 5 l/min). All prostheses underwent X-ray, computed tomography (CT)-Scan and photographic examination for evaluation of progressive calcification. Leaflet kinematics were visualized with a high-speed camera. RESULTS: Pericardial valves demonstrated faster degeneration with significantly larger radiographic areas of leaflet calcification (16.5+/-4.3% versus 5.6%+/-2.0%) and also significantly higher Ca-uptake (170+/-71 microg/mg versus 103+/-49 microg/mg) after 6 weeks. Despite degeneration systolic function remained superior for pericardial valves (mean effective orifice area [EOA] 1.52+/-0.05 versus 1.28+/-0.11 cm2, P<0.01), but leaflet kinematics showed longer closing times (135+/-11 msec versus 85+/-9 msec after 6 weeks) accompanied by higher regurgitant flow (7.8+/-1.12 mL versus 1.2+/-0.28 mL, P<0.001). CONCLUSION: In vitro pericardial valves calcified faster and more severe than porcine valves leading to impaired diastolic function with prolongation of closing times and higher closing volume. Systolic function remained almost undisturbed by the calcification process. As a consequence in clinical settings, follow-up examinations for structural valve deterioration in porcine valves should focus on systolic performance, in pericardial valves on diastolic function.

Spherical dilatation of the apex in failing left ventricles: a target for surgical remodelling techniques.

AIM: The present study investigates the geometry of failing left ventricles with a special focus on apical deformation. A new surgical remodelling technique is evaluated. METHODS: In 124 patients with impaired left ventricular function (EF<40%) undergoing coronary artery bypass grafting (CABG) left ventricular (LV) geometry was evaluated by MRI scanning before and after surgery. Besides the sphericity index (SI) two further indices were calculated, longitudinal EF (LEF) and an apical conicity index (ACI). The results were compared to 15 patients with coronary heart disease and normal LV function and 10 test persons. In 35 patients with impaired LV function perpendicular apical compression (AC) stitches were placed. RESULTS: In failing left ventricles indexed LV length increased (5.3 ± 0.6 cm/m2 vs. 4.7 ± 0.8 cm/m2 in control patients and 4.6 ± 0.3 cm/m2 in test persons, P=0.03). LEF was reduced (6% ± 4 versus 22% ± 6 and 19% ± 7 P=0.04). The classical SI was 0.56 ± 0.06 in heart failure patients, 0.50 ± 0.05 in control patients and 0.48 ± 0.04 in test persons. The ACI were 0.75 ± 0.06, 0.58 ± 0.06 and 0.57 ± 0.04 respectively (P<0.05), indicating a pronounced dilatation at the apex. After apical compression LEF improved to 15 ± 1%, the ACI to 0.64 ± 0.04 (P=0.04). LVEDV (166 ± 11 mL [AC] vs. 196 ± 14 mL [without AC]) as well as LV-EF (48 ± 3% [AC] vs. 36 ± 2% [without AC]) significantly improved only after remodelling (P<0.05). CONCLUSION: Apical compression improved ventricular geometry and ventricular function in patients with dialatation of the left ventricular apex.

[Pericardial effusion. Differential diagnostics, surveillance and treatment]. / Perikarderguss. Differenzierte Diagnostik, Überwachung und Therapie.

Cardiac tamponade can be a life-threatening condition due to the high variability of clinical symptoms and the associated risk of rapid hemodynamic deterioration. Therefore, accurate diagnosis followed by immediate intervention is necessary. Common clinical features of cardiac tamponade are pulsus paradoxus, tachycardia, elevated jugular venous pressure and hypotension; however, although these can be indicative of cardiac tamponade they are non-specific. Instant confirmation of the clinical diagnosis of cardiac tamponade can be pursued with echocardiography which also enables a clear estimation of the current hemodynamic situation. Thus in contemporary clinical practice echocardiography plays a key role in the management of cardiac tamponade and must be consulted with regards to final treatment decisions. Common practice includes pericardial puncture under echocardiographic and/or X-ray guidance but only in cases of significantly sized pericardial effusions. Whenever there is a limited sized but hemodynamically significant effusion, inferior pericardiotomy should be the preferred treatment strategy. In cases of cardiac tamponade following chest trauma a full median sternotomy can be a suitable approach for surgical treatment.

Impact of different pacing modes on left ventricular function following cardiopulmonary bypass.

BACKGROUND: Patients with severely impaired left ventricular (LV) function often demonstrate prolonged inter- and intraventricular conduction. This prospective study investigates hemodynamic effects and outcomes of perioperative temporary biventricular pacing in patients with heart failure undergoing heart surgery. METHODS: 80 consecutive cardiac surgery patients with a LV ejection fraction below 35 % received biventricular stimulation via temporary myocardial electrodes. Group 1 consisted of 40 patients with LV dilatation (mean LVEDD 65 +/- 5 mm), Group 2 of 40 patients with normal or slightly dilated LV (mean LVEDD 52 +/- 4 mm). RESULTS: Hemodynamic parameters were measured immediately, 6 and 24 hours after operation. An increase of cardiac index (CI) and arterial blood pressure with biventricular pacing was observed in 27 patients (Group 1/67.5 %) versus 22 patients (Group 2/55 %) from 2.4 +/- 0.7 l/min/m2 to 3.5 +/- 0.5 l/min/m2 ( P < 0.01). This benefit persisted 6 and 24 hours postoperatively. The remaining patients already showed a higher cardiac index prior to pacing (3.7 +/- 0.9 l/min/m2). In Group 1, the duration of ventilation support and time in the intensive care unit of responding patients was shorter. QRS duration before surgery was not predictive for the response to biventricular pacing. CONCLUSIONS: In the majority of patients with reduced LV function, temporary biventricular pacing improves CO and arterial blood pressure after surgery, especially when LV dilatation is present.

Hemodynamic effects of left ventricular pacing site in an animal model of heart failure.

BACKGROUND: This study investigates how different left ventricular epicardial and endocardial pacing sites influence hemodynamic performance in an animal model of heart failure (HF). METHODS: In six adult sheep, dilated HF was induced by rapid pacing. Subsequently, endocardial left ventricular stimulation was performed using a 64-electrode basket catheter. Epicardial pacing was achieved with temporary electrodes. RESULTS: Baseline cardiac output (CO) was 2.7 +/- 0.4 l/min and improved significantly with lateral wall epicardial and endocardial stimulation (3.6 +/- 0.7 and 3.8 +/- 0.65 l/min), whereas right ventricular pacing led to lower CO (2.1 +/- 0.5 and 2.0 +/- 0.9 l/min). In the optimal pacing location arterial pressure, pulmonary capillary wedge pressure (pcwp) and LV diameters improved significantly. Right ventricular pacing impaired hemodynamics, while no change was observed in the LV inferior wall and apex pacing. CONCLUSION: Endocardial and epicardial pacing of the lateral wall led to an improvement in LV function while right ventricular pacing induced a further reduction of LV performance. As this optimal pacing site cannot always be reached via the coronary sinus, surgical implantation of epicardial electrodes should be considered in all non-responding patients.

Detection of vein graft disease using 4-row computed tomography. Evaluation of coronary bypass graft patency and correlation with the Ca-score.

BACKGROUND: Multi-row computed tomography (MDCT) is a promising non-invasive technique and capable of rapid imaging of cardiac structures, including coronary arteries and bypass grafts during a single held breath. In this study, we evaluated coronary artery bypass graft (CABG) patency by comparing 4-slice computed tomography with conventional contrast angiography. One disadvantage of MDCT is the limited diagnostic accuracy with + increased calcification of the grafts. Therefore, the correlation between Ca-grading and diagnostic accuracy was examined. METHODS: We examined 30 patients with 104 bypass grafts with a 4-row MDCT scanner. On the basis of the Ca-score, patients were divided into 3 groups. RESULTS: It was possible to assess the exact degree of stenosis in 25 of 32 > 50% stenoses with 4-row MDCT, 7 stenoses were underestimated. All occlusions in 21 patients were identified correctly, 33 graft segments were underestimated in MDCT, of which 28 were in the group with a Ca-score of > 800. CONCLUSIONS: MDCT allows non-invasive angiographic evaluation of coronary bypass grafts with a high diagnostic accuracy. However, the method strongly depends on the degree of vascular calcification and underrates the degree of stenosis subject to the Ca-score. This is a distinct limitation in distal vascular segments of small calibre which cannot be validly displayed. In patients with low or moderate Ca-score values, MDCT coronary angiography is promising new technique with a high diagnostic accuracy for the detection of graft stenosis or occlusions.

MR-based coronary artery blood velocity measurements in patients without coronary artery disease.

To evaluate the feasibility of MR-based coronary blood velocity measurements (MRvenc) in patients without coronary artery disease (CAD). Eighty-three patients with angiographically excluded CAD received MRvenc of the proximal segments of both coronary arteries (CAs). Using a retrospectively ECG-gated breath-hold phase-contrast FLASH sequence with high temporal resolution, flow data were technically acquirable in 137/166 (83%) CAs. Quantification and analysis of blood velocities in systole and diastole of both CAs were performed. Biphasic velocity profiles were found in 83/100 CAs. Median systolic and diastolic velocities differed significantly in LCA (19 cm/s, 24 cm/s; P<0.0001) and RCAs (14 cm/s, 16 cm/s; P<0.01). The diastolic/systolic velocity ratio was calculated in LCAs and RCAs with a median of 1.3 and 1.1, respectively. The velocity profiles of the remaining CAs were monophasic (17 CAs) or revealed severe alterations of the physiologic velocity profile with reduced flow undulations and steady velocities (37 CAs). Optimized clinical MRvenc is feasible to quantify blood velocities in the CAs. Potential indications are (1) non-invasive monitoring of patients after aortic valve reconstruction as well as (2) detection of asymptomatic CAD patients.