Pacing therapy for atrioventricular dromotropathy: a combined computational-experimental-clinical study.

AIMS: Investigate haemodynamic effects, and their mechanisms, of restoring atrioventricular (AV)-coupling using pacemaker therapy in normal and failing hearts in a combined computational-experimental-clinical study. METHODS AND RESULTS: Computer simulations were performed in the CircAdapt model of the normal and failing human heart and circulation. Experiments were performed in a porcine model of AV dromotropathy. In a proof-of-principle clinical study, left ventricular (LV) pressure and volume were measured in 22 heart failure (HF) patients (LV ejection fraction <35%) with prolonged PR interval (>230 ms) and narrow or non-left bundle branch block QRS complex. Computer simulations and animal studies in normal hearts showed that restoring of AV-coupling with unchanged ventricular activation sequence significantly increased LV filling, mean arterial pressure, and cardiac output by 10-15%. In computer simulations of failing hearts and in HF patients, reducing PR interval by biventricular (BiV) pacing (patients: from 300 ± 61 to 137 ± 30 ms) resulted in significant increases in LV stroke volume and stroke work (patients: 34 ± 40% and 26 ± 31%, respectively). However, worsening of ventricular dyssynchrony by using right ventricular (RV) pacing abrogated the benefit of restoring AV-coupling. In model simulations, animals and patients, the increase of LV filling and associated improvement of LV pump function coincided with both larger mitral inflow (E- and A-wave area) and reduction of diastolic mitral regurgitation. CONCLUSION: Restoration of AV-coupling by BiV pacing in normal and failing hearts with prolonged AV conduction leads to considerable haemodynamic improvement. These results indicate that BiV or physiological pacing, but not RV pacing, may improve cardiac function in patients with HF and prolonged PR interval.

Symptomatic mediastinal mass in a 32-year-old male.

Most bronchogenic cysts are found incidentally and clinicians should be aware of an atypical case presentation. Total surgical resection is the treatment of choice of a bronchogenic cyst, especially in symptomatic patients. https://bit.ly/3uQrFXo.

Veno-Arterial Extracorporeal Life Support in Heart Transplant and Ventricle Assist Device Centres. Meta-analysis.

AIMS: Because reported mortality on veno-arterial (V-A) extracorporeal life support (ECLS) substantially varies between centres, the aim of the current analysis was to assess the outcomes between units performing heart transplantation and/or implanting ventricular assist device (HTx/VAD) vs. non-HTx/VAD units in patients undergoing V-A ECLS for cardiogenic shock. METHODS AND RESULTS: Systematic search according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses was performed using PubMed/MEDLINE databases until 30 November 2019. Articles reporting in-hospital/30-day mortality and centre's HTx/VAD status were included. In-hospital outcomes and long-term survival were analysed in subgroup meta-analysis. A total of 174 studies enrolling n = 13 308 patients were included with 20 series performed in non-HTx/VAD centres (1016 patients, 7.8%). Majority of patients underwent V-A ECLS for post-cardiotomy shock (44.2%) and acute myocardial infarction (20.7%). Estimated overall in-hospital mortality was 57.2% (54.9-59.4%). Mortality rates were higher in non-HTx/VAD [65.5% (59.8-70.8%)] as compared with HTx/VAD centres [55.8% (53.3-58.2%)], P < 0.001. Estimated late survival was 61.8% (55.7-67.9%) without differences between non-HTx/VAD and HTx/VAD centres: 66.5% (30.3-1.02%) vs. 61.7% (55.5-67.8%), respectively (P = 0.797). No differences were seen with respect to ECLS duration, limb complications, and reoperations for bleeding, kidney injury, and sepsis. Yet, weaning rates were higher in HTx/VAD vs. non-HTx/VAD centres: 58.7% (56.2-61.1%) vs. 48.9% (42.0-55.9%), P = 0.010. Estimated rate of bridge to heart transplant was 6.6% (5.2-8.3%) with numerical, yet not statistically significant, difference between non-HTx/VAD [2.7% (0.8-8.3%)] as compared with HTx/VAD [6.7% (5.3-8.6%)] (P = 0.131). CONCLUSIONS: Survival after V-A ECLS differed according to centre's HTx/VAD status. Potentially different risk profiles of patients must be taken account for before definite conclusions are drawn.

The impact of Centre's heart transplant status and volume on in-hospital outcomes following extracorporeal membrane oxygenation for refractory post-cardiotomy cardiogenic shock: a meta-analysis.

BACKGROUND: Postcardiotomy cardiogenic shock (PCS) that is refractory to inotropic support remains a major concern in cardiac surgery and is almost universally fatal unless treated with mechanical support. While reported mortality rates on ECMO vary from center to center, aim of the current report is assess if the outcomes differ between centres according to volume and heart transplantation status. METHODS: A systematic search was performed according to PRISMA statement using PubMed/Medline databases between 2010 and 2018. Relevant articles were scrutinized and included in the meta-analysis only if reporting in-hospital/30-day mortality and heart transplantation status of the centre. Paediatric and congenital heart surgery-related studies along with those conducted in the setting of veno-venous ECMO for respiratory distress syndrome were excluded. Differences were assessed by means of subgroup meta-analysis and meta-regression. RESULTS: Fifty-four studies enrolling N = 4421 ECMO patients were included. Of those, 6 series were performed in non-HTx centres (204 pts.;4.6%). Overall 30-day survival (95% Confidence Intervals) was 35.3% (32.5-38.2%) and did not statistically differ between non-HTx: 33.3% (26.8-40.4%) and HTx centres: 35.7% (32.7-38.8%); Pinteraction = 0.531. There was no impact of centre volume on survival as well: ßcoef = 0.0006; P = 0.833. No statistical differences were seen between HTx and non-HTx with respect to ECMO duration, limb complications, reoperations for bleeding, kidney injury and sepsis. There were however significantly less neurological complications in the HTx as compared to non-HTx centres: 11.9% vs 19.5% respectively; P = 0.009; an inverse relationship was seen for neurologic complications in centres performing more ECMOs annually ßcoef = - 0.0066; P = 0.031. Weaning rates and bridging to HTx and/or VADs were higher in HTx facilities. CONCLUSIONS: There was no apparent difference in survival after ECMO implantation for refractory PCS according to centre's ECMO volume and transplantation status. Potentially different risk profiles of patients in these centres must be taken account for before definite conclusions are drawn.

Baseline surgical status and short-term mortality after extracorporeal membrane oxygenation for post-cardiotomy shock: a meta-analysis.

OBJECTIVE: While reported mortality rates on post-cardiotomy extracorporeal membrane oxygenation vary from center to center, impact of baseline surgical status (elective/urgent/emergency/salvage) on mortality is still unknown. METHODS: A systematic search was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement using PubMed/Medline databases until March 2018 using the keywords "postcardiotomy," "cardiogenic shock," "extracorporeal membrane oxygenation," and "extracorporeal life support." Relevant articles were scrutinized and included in the meta-analysis only if reporting in-hospital/30-day mortality and baseline surgical status. The correlations between mortality and percentage of elective/urgent/emergency cases were investigated. Inference analysis of baseline status and extracorporeal membrane oxygenation complications was conducted as well. RESULTS: Twenty-two studies (conducted between 1993 and 2017) enrolling N = 2,235 post-cardiotomy extracorporeal membrane oxygenation patients were found. Patients were mostly of non-emergency status (65.2%). Overall in-hospital/30-day mortality event rate (95% confidence intervals) was 66.7% (63.3-69.9%). There were no differences in in-hospital/30-day mortality with respect to baseline surgical status in the subgroup analysis (test for subgroup differences; p = 0.406). Similarly, no differences between mortality in studies enrolling <50 versus ⩾50% of emergency/salvage cases was found: respective event rates were 66.9% (63.1-70.4%) versus 64.4% (57.3-70.8%); p = 0.525. Yet, there was a significant positive association between increasing percentage of emergency/salvage cases and rates of neurological complications (p < 0.001), limb complications (p < 0.001), and bleeding (p = 0.051). Incidence of brain death (p = 0.099) and sepsis (p = 0.134) was increased as well. CONCLUSION: Other factors than baseline surgical status may, to a higher degree, influence the mortality in patients treated with extracorporeal membrane oxygenation for post-cardiotomy cardiogenic shock. Baseline status, however, strongly influences the complication occurrence while on extracorporeal membrane oxygenation.

Long-term survival and major outcomes in post-cardiotomy extracorporeal membrane oxygenation for adult patients in cardiogenic shock.

Extracorporeal membrane oxygenation (ECMO) in the veno-arterial (VA) configuration is an established method for the treatment of refractory cardiogenic shock. Such a condition characterizes the postoperative course of approximatively 1% of cardiac surgery patients. Although some studies have reported ECMO-related short-term results, little is known about the long-term outcomes of VA-ECMO therapy in the post-cardiotomy setting. Therefore, an extensive literature search was conducted regarding articles published after 1990 reporting postoperative ECMO use. PubMed, EMBASE and Web of Science were searched for sources. In-hospital mortality was high in post-cardiotomy VA-ECMO patients, ranging from 24.8% to 52%. Long-term results were poorly reported. However, based on the limited information available, hospital survivors showed a favorable outcome, with improvement in overall clinical condition, quality of life and limited hospital readmission for cardiac-related events. To conclude, in-hospital outcome in post-cardiotomy ECMO is often unfavorable, post-discharge results show satisfactory condition, with stable improvement of overall patient clinical status and low rate of hospital readmission and cardiac-related adverse events. Data reporting is, however, scarce and hence new and detailed studies are still warranted to investigate such aspects.

The Left and Right Ventricles Respond Differently to Variation of Pacing Delays in Cardiac Resynchronization Therapy: A Combined Experimental- Computational Approach.

Introduction: Timing of atrial, right (RV), and left ventricular (LV) stimulation in cardiac resynchronization therapy (CRT) is known to affect electrical activation and pump function of the LV. In this study, we used computer simulations, with input from animal experiments, to investigate the effect of varying pacing delays on both LV and RV electrical dyssynchrony and contractile function. Methods: A pacing protocol was performed in dogs with atrioventricular block (N = 6), using 100 different combinations of atrial (A)-LV and A-RV pacing delays. Regional LV and RV electrical activation times were measured using 112 electrodes and LV and RV pressures were measured with catheter-tip micromanometers. Contractile response to a pacing delay was defined as relative change of the maximum rate of LV and RV pressure rise (dP/dtmax) compared to RV pacing with an A-RV delay of 125 ms. The pacing protocol was simulated in the CircAdapt model of cardiovascular system dynamics, using the experimentally acquired electrical mapping data as input. Results: Ventricular electrical activation changed with changes in the amount of LV or RV pre-excitation. The resulting changes in dP/dtmax differed markedly between the LV and RV. Pacing the LV 10-50 ms before the RV led to the largest increases in LV dP/dtmax. In contrast, RV dP/dtmax was highest with RV pre-excitation and decreased up to 33% with LV pre-excitation. These opposite patterns of changes in RV and LV dP/dtmax were reproduced by the simulations. The simulations extended these observations by showing that changes in steady-state biventricular cardiac output differed from changes in both LV and RV dP/dtmax. The model allowed to explain the discrepant changes in dP/dtmax and cardiac output by coupling between atria and ventricles as well as between the ventricles. Conclusion: The LV and the RV respond in a opposite manner to variation in the amount of LV or RV pre-excitation. Computer simulations capture LV and RV behavior during pacing delay variation and may be used in the design of new CRT optimization studies.

Protracted aortic valve closure during peripheral veno-arterial extracorporeal life support: is intra-aortic balloon pump an effective solution?

BACKGROUND: Left ventricular (LV) afterload increase with protracted aortic valve (AV) closure may represent a complication of veno-arterial extracorporeal membrane oxygenation (V-A ECMO). The aim of the present study was to assess the effects of an intra-aortic balloon pump (IABP) to overcome such a hemodynamic shortcoming in patients submitted to peripheral V-A ECMO. METHODS: Among 184 adult patients who were treated with peripheral V-A ECMO support at Medical University Center Maastricht Hospital between 2007 and 2018, patients submitted to IABP implant for protracted AV closure after V-A ECMO implant were retrospectively identified. All clinical and hemodynamic data, including echocardiographic monitoring, were collected and analyzed. RESULTS: During the study period, 10 subjects (mean age 60 years old, 80% males) underwent IABP implant after peripheral V-A ECMO positioning due to the diagnosis of protracted AV closure and inefficient LV unloading as assessed by echocardiography and an absence of pulsation in the arterial pressure wave. Recovery of blood pressure pulsatility and enhanced LV unloading were observed in 8 patients after IABP placement, with no significant differences in the main hemodynamic parameters, inotropic therapy or in the ECMO flow (p=0.48). The weaning rate in this patient subgroup (mean ECMO duration 8 days), however, was only 10%, with another patient finally transplanted, leading to a 20% survival-to-hospital discharge. CONCLUSION: IABP placement was an effective solution in order to reverse the protracted AV closure and impaired LV unloading observed during peripheral V-A ECMO support. However, the impact on the weaning rate and survival needs further investigations.

The unstoppable heart: an aortocoronary fistula in coronary artery bypass grafting.

This case report describes a coronary bypass surgery case in which cardioplegic arrest was impossible due to an aortacoronary fistula that was visualized using 3-dimensional computer tomography (CT) angiography postoperatively. Aortacoronary fistulas are protective in coronary artery disease but can severely complicate cardiac surgery and might require CT imaging in the preoperative workup.

In-hospital outcome of post-cardiotomy extracorporeal life support in adult patients: the 2007-2017 Maastricht experience.

OBJECTIVES: The use of post-cardiotomy extracorporeal life support (PC-ECLS) has increased worldwide over the past years but a concurrent decrease in survival to hospital discharge has also been observed. We analysed use and outcome of PC-ECLS at the Maastricht University Medical Center. DESIGN: A retrospective study of a single-centre PC-ECLS cohort. Patient characteristics and in-hospital outcomes were evaluated. SETTING: Patients who underwent PC-ECLS due to intra- or peri-operative cardiogenic shock or cardiac arrest were included. Descriptive statistics were analysed and frequency analysis and testing of group differences were performed. PARTICIPANTS: Eighty-six patients who received PC-ECLS between October 2007 and June 2017 were included. The mean age of the population was 65 years (range, 31-86 years), and 65% were men. MAIN OUTCOME MEASURES: Survival rates were calculated and PC-ECLS management data and complications were assessed. RESULTS: Pre-ECLS procedures were isolated coronary artery bypass grafting (CABG) (22%), isolated valve surgery (16%), thoracic aorta surgery (4%), a combination of CABG and valve surgery (21%) or other surgery (24%). PC-ECLS was achieved via central cannulation in 17%, peripheral cannulation in 65%, or by a combination in 17%. The median duration of PC-ECLS was 5.0 days (IQR, 6.0 days). Weaning was achieved in 49% of patients, and 37% survived to discharge. Post-operative bleeding (overall rate, 42%) showed a trend towards a reduced rate over more recent years. CONCLUSIONS: Our experience confirms an increased use of PC-ECLS during the last 10 years and shows that, by carefully addressing patient management and complications, survival rat e may be satisfactory, and improved outcome may be achieved in such a challenging ECLS setting.

Modalities and Effects of Left Ventricle Unloading on Extracorporeal Life support: a Review of the Current Literature.

INTRODUCTION/AIM: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) support is increasingly used in refractory cardiogenic shock and cardiac arrest, but is characterized by a rise in afterload of the left ventricle (LV) which may ultimately either further impair or delay cardiac contractility improvement. The aim of this study was to provide a comprehensive overview regarding the different LV venting techniques and results currently available in the literature. METHODS: A systematic literature search was performed in the PubMed database: 207 articles published between 1993 and 2016 were included. Papers dealing with pre-clinical studies, overlapping series, and association with other assist devices were excluded from the review, with 45 published papers finally selected. Heterogeneous indications for LV unloading were reported. The selected literature was divided into subgroups, according to the location or the performed procedure for LV venting. RESULTS: Case reports or case series accounted for 60% of the papers, while retrospective study represented 29% of them. Adult series were present in 67%, paediatric patients in 29%, and a mixed population in 4%. LV unloading was performed percutaneously in 84% of the cases. The most common locations of unloading was the left atrium (31%), followed by indirect unloading (intra-aortic balloon pump) (27%), trans-aortic (27%), LV (11%), and pulmonary artery (4%). Percutaneous trans-septal approach was reported in 22%. Finally, the unloading was conducted surgically in 16%,with open chest surgery in 71%, and minimally invasive surgery in 29% of surgical cases. CONCLUSION: Nowadays, only a few data are available about left heart unloading in V-A ECMO support. Despite the well-known controversy, IABP remains widely used in combination with V-A ECMO. Percutaneous approaches utilizing unloading devices is becoming an increasingly used option. However, further studies are required to establish the optimal LV unloading method.

Exploring the Electrophysiologic and Hemodynamic Effects of Cardiac Resynchronization Therapy: From Bench to Bedside and Vice Versa.

Cardiac resynchronization therapy (CRT) is an important therapy for heart failure patients with prolonged QRS duration. In patients with left bundle branch block the altered left ventricular electrical activation results in dyssynchronous, inefficient contraction of the left ventricle. CRT aims to reverse these changes and to improve cardiac function. This article explores the electrophysiologic and hemodynamic changes that occur during CRT in patient and animal studies. It also addresses how novel techniques, such as multipoint and endocardial pacing, can further improve the electromechanical response.

Exploring the Electrophysiologic and Hemodynamic Effects of Cardiac Resynchronization Therapy: From Bench to Bedside and Vice Versa.

Cardiac resynchronization therapy (CRT) is an important therapy for heart failure patients with prolonged QRS duration. In patients with left bundle branch block the altered left ventricular electrical activation results in dyssynchronous, inefficient contraction of the left ventricle. CRT aims to reverse these changes and to improve cardiac function. This article explores the electrophysiologic and hemodynamic changes that occur during CRT in patient and animal studies. It also addresses how novel techniques, such as multipoint and endocardial pacing, can further improve the electromechanical response.