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1.
Article in English | MEDLINE | ID: mdl-38787287

ABSTRACT

Aortic root reconstruction during aortic root replacement for a patient with prosthetic valve endocarditis and aortic root abscess can be a difficult procedure with many possible complications. In this video case report, we describe our novel technique using a single bovine pericardial patch that avoids deep stitches or external sutures to support the friable annulus. Compared with more standard methods, this approach has shorter cross-clamp and cardiopulmonary bypass times and is less demanding technically.


Subject(s)
Aortic Valve , Heart Valve Prosthesis , Humans , Aortic Valve/surgery , Heart Valve Prosthesis Implantation/methods , Prosthesis-Related Infections/surgery , Prosthesis-Related Infections/diagnosis , Prosthesis-Related Infections/etiology , Male , Endocarditis/surgery , Endocarditis, Bacterial/surgery , Endocarditis, Bacterial/diagnosis , Pericardium/transplantation , Plastic Surgery Procedures/methods , Middle Aged , Animals , Cattle
2.
J Am Heart Assoc ; 13(10): e033590, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38742529

ABSTRACT

BACKGROUND: The new heart allocation policy places veno-arterial extracorporeal membrane oxygenation (VA-ECMO)-supported heart transplant (HT) candidates at the highest priority status. Despite increasing evidence supporting left ventricular (LV) unloading during VA-ECMO, the effect of LV unloading on transplant outcomes following bridging to HT with VA-ECMO remains unknown. METHODS AND RESULTS: From October 18, 2018 to March 21, 2023, 624 patients on VA-ECMO at the time of HT were identified in the United Network for Organ Sharing database and were divided into 2 groups: VA-ECMO alone (N=384) versus VA-ECMO with LV unloading (N=240). Subanalysis was performed in the LV unloading group: Impella (N=106) versus intra-aortic balloon pump (N=134). Recipient age was younger in the VA-ECMO alone group (48 versus 53 years, P=0.018), as was donor age (VA-ECMO alone, 29 years versus LV unloading, 32 years, P=0.041). One-year survival was comparable between groups (VA-ECMO alone, 88.0±1.8% versus LV unloading, 90.4±2.1%; P=0.92). Multivariable Cox hazard model showed LV unloading was not associated with posttransplant mortality after HT (hazard ratio, 0.92; P=0.70). Different LV unloading methods had similar 1-year survival (intra-aortic balloon pump, 89.2±3.0% versus Impella, 92.4±2.8%; P=0.65). Posttransplant survival was comparable between different Impella versions (Impella 2.5, versus Impella CP, versus Impella 5.0, versus Impella 5.5). CONCLUSIONS: Under the current allocation policy, LV unloading did not impact waitlist outcome and posttransplant survival in patients bridged to HT with VA-ECMO, nor did mode of LV unloading. This highlights the importance of a tailored approach in HT candidates on VA-ECMO, where routine LV unloading may not be universally necessary.


Subject(s)
Extracorporeal Membrane Oxygenation , Heart Transplantation , Heart-Assist Devices , Humans , Extracorporeal Membrane Oxygenation/methods , Male , Female , Middle Aged , Adult , Ventricular Function, Left , Retrospective Studies , Tissue and Organ Procurement/methods , Treatment Outcome , United States/epidemiology , Heart Failure/physiopathology , Heart Failure/mortality , Heart Failure/therapy , Heart Failure/surgery , Time Factors , Waiting Lists/mortality , Intra-Aortic Balloon Pumping
3.
J Pers Med ; 14(3)2024 Feb 22.
Article in English | MEDLINE | ID: mdl-38540978

ABSTRACT

The 2018 heart allocation system has significantly influenced heart transplantation and left ventricular assist device (LVAD) utilization. Our study aims to investigate age-related outcomes following LVAD implantation in the post-allocation era. Using the National Inpatient Sample, we analyzed data from 7375 patients who underwent LVAD implantation between 2019 and 2020. The primary endpoint was in-hospital mortality following LVAD implantation, stratified by age categories. The age groups were 18-49, 50-59, 60-69, and over 70. These represented 26%, 26%, 31%, and 17% of patients, respectively. Patients aged 60-69 and those over 70 exhibited higher in-hospital mortality rates of 12% and 17%, respectively, compared to younger age groups (7% for 18-49 and 6% for 50-59). The age groups 60-69 and over 70 were independent predictors of mortality, with adjusted odds ratios of 1.99 (p = 0.02; 95% confidence interval [CI], 1.12-3.57) and 2.88 (p = 0.002; 95% CI, 1.45-5.71), respectively. Additionally, a higher Charlson Comorbidity Index was associated with increased in-hospital mortality risk (adjusted odds ratio 1.39; p = 0.02; 95% CI, 1.05-1.84). Additionally, patients above 70 experienced a statistically shorter length of stay. Nonhome discharge was found to be significantly high across all age categories. However, the difference in hospitalization cost was not statistically significant across the age groups. Our study highlights that patients aged 60 and above face an increased risk of in-hospital mortality following LVAD implantation in the post-allocation era. This study sheds light on age-related outcomes and emphasizes the importance of considering age in LVAD patient selection and management strategies.

4.
Heart ; 110(5): 331-336, 2024 Feb 12.
Article in English | MEDLINE | ID: mdl-37648437

ABSTRACT

OBJECTIVE: Aortic dissection and aortic aneurysm rupture are aortic emergencies and their clinical outcomes have improved over the past two decades; however, whether this has translated into lower mortality across countries remains an open question. The purpose of this study was to compare mortality trends from aortic dissection and rupture between the UK, Japan, the USA and Canada. METHODS: We analysed the WHO mortality database to determine trends in mortality from aortic dissection and rupture in four countries from 2000 to 2019. Age-standardised mortality rates per 100 000 persons were calculated, and annual percentage change was estimated using joinpoint regression. RESULTS: Age-standardised mortality rates per 100 000 persons from aortic dissection and rupture in 2019 were 1.04 and 1.80 in the UK, 2.66 and 1.16 in Japan, 0.76 and 0.52 in the USA, and 0.67 and 0.81 in Canada, respectively. There was significantly decreasing trends in age-standardised mortality from aortic rupture in all four countries and decreasing trends in age-standardised mortality from aortic dissection in the UK over the study period. There was significantly increasing trends in mortality from aortic dissection in Japan over the study period. Joinpoint regression identified significant changes in the aortic dissection trends from decreasing to increasing in the USA from 2010 and Canada from 2012. In sensitivity analyses stratified by sex, similar trends were observed. CONCLUSIONS: Trends in mortality from aortic rupture are decreasing; however, mortality from aortic dissection is increasing in Japan, the USA and Canada. Further study to explain these trends is warranted.


Subject(s)
Aortic Dissection , Aortic Rupture , Humans , Japan/epidemiology , Canada/epidemiology , United Kingdom/epidemiology
5.
Am J Cardiol ; 212: 13-22, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-38008347

ABSTRACT

Hybrid coronary revascularization (HCR) is an alternative option to conventional coronary artery bypass grafting (CABG), but the long-term outcomes of HCR versus CABG remain unclear. We aimed to analyze the long-term outcomes after HCR and CABG for patients with multivessel coronary artery disease using meta-analysis. A systemic literature search of PubMed and EMBASE was performed from inception to March 2023. Studies reporting Kaplan-Meier curves with follow-up ≥1 year were included. The primary outcome was all-cause mortality, and the secondary outcomes were major adverse cardiac and cerebrovascular events (MACCEs) and repeat revascularization. In total, 13 studies (1 randomized controlled trial and 12 propensity-score matched observational studies) were analyzed. The mean follow-up period was 5.1 ± 3.1 years. HCR was associated with similar overall mortality (hazard ratio [HR] 1.09, 95% confidence interval [CI] 0.87 to 1.36), significantly higher incidence of MACCEs (HR 1.49, 95% CI 1.07 to 2.06), and repeat revascularization (HR 2.01, 95% CI 1.53 to 2.64) compared with CABG. In phase-specific analysis, the mortality rate was similar, and the incidence of repeat revascularization was higher in HCR regardless of phases. The incidence of MACCEs was higher in HCR during the mid-term phase (1 to 5 years), but it was similar during the long-term phase (long-term: ≥5 years). In conclusion, despite the higher incidence of MACCEs and repeat revascularization compared with CABG, HCR offered a similar long-term survival. Even longer-term follow-up and randomized controlled trials with a large population are warranted to investigate the role of HCR for multivessel coronary artery disease.


Subject(s)
Coronary Artery Disease , Percutaneous Coronary Intervention , Humans , Percutaneous Coronary Intervention/adverse effects , Treatment Outcome , Coronary Artery Bypass/adverse effects , Incidence
6.
J Thorac Dis ; 15(9): 4693-4702, 2023 Sep 28.
Article in English | MEDLINE | ID: mdl-37868903

ABSTRACT

Background: The optimal aortic valve substitute for non-elderly adults remains controversial. Recently, considerable data on the Ross procedure have accumulated. This study aimed to analyze long-term outcomes following the Ross procedure from the current literature using a meta-analysis of time-to-event outcomes. Methods: A literature search was performed with MEDLINE, EMBASE, Cochrane Library, Web of Science, and Google Scholar through June 2022; studies reporting clinical outcomes of the Ross procedure beyond 20 years were included for analysis. The outcomes of interest were late survival and freedom from surgical or percutaneous reintervention of the autograft or right ventricular outflow tract (RVOT). Results: Six studies, including 4,910 patients (3,601 males), were identified and analyzed. Survival rate at 5, 10, 15, and 20 years was 99.9%±0.1%, 97.6%±0.5%, 94.3%±0.9%, and 87.4%±1.9%. Freedom from autograft reintervention at 5, 10, 15, and 20 years was 97.7%±0.5%, 95.3%±0.7%, 91.4%±1.2%, 84.8%±2.5%. Freedom from RVOT reintervention was 99.0%±0.3%, 99.0%±0.3%, 97.5%±0.7%, 93.3%±1.8%. Freedom from any valve reintervention (either autograft or RVOT) at 5, 10, 15, and 20 years was 95.8%±0.6%, 92.6%±0.9%, 88.5%±1.2%, 80.8%±2.5%. Conclusions: This meta-analysis demonstrated that the Ross procedure was confirmed to provide excellent survival despite the need for reintervention of autograft or RVOT in approximately 20% of patients at 20 years.

7.
Catheter Cardiovasc Interv ; 102(7): 1291-1300, 2023 12.
Article in English | MEDLINE | ID: mdl-37890015

ABSTRACT

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is as an alternative treatment to surgical AVR, but the long-term outcomes of TAVR remain unclear. AIMS: This study aimed to analyze long-term outcomes following TAVR using meta-analysis. METHODS: A literature search was performed with MEDLINE, EMBASE, Cochrane Library, Web of Science, and Google Scholar through November 2022; studies reporting clinical outcomes of TAVR with follow-up periods of ≥8 years were included. The outcomes of interest were overall survival and/or freedom from structural valve deterioration (SVD). Surgical risk was assessed with the Society of Thoracic Surgeons (STS) predicted risk of mortality (PROM) score. A subgroup analysis was conducted for intermediate-/high-surgical risk patients only. RESULTS: Eleven studies including 5458 patients were identified and analyzed. The mean age was 82.0 ± 6.5 years, and mean STS PROM score ranged from 2.9 to 10.6%. Survival rate at 5 and 10 years was 47.7% ± 1.4% and 12.1 ± 2.0%. Five studies including 1509 patients were analyzed for SVD. Freedom from SVD at 5 and 8 years was 95.5 ± 0.7% and 85.1 ± 3.1%. Similar results for survival and SVD were noted in the subgroup analysis of intermediate-/high-risk patients. CONCLUSIONS: Following TAVR, approximately 88% of patients died within 10 years, whereas 85% were free from SVD at 8 years. These date suggest that baseline patient demographic have the greatest impact on survival, and SVD does not seem to have a prognostic impact in this population. Further investigations on longer-term outcomes of younger and lower-risk patients are warranted.


Subject(s)
Aortic Valve Stenosis , Heart Valve Prosthesis Implantation , Transcatheter Aortic Valve Replacement , Humans , Aged , Aged, 80 and over , Transcatheter Aortic Valve Replacement/adverse effects , Aortic Valve/diagnostic imaging , Aortic Valve/surgery , Heart Valve Prosthesis Implantation/adverse effects , Aortic Valve Stenosis/diagnostic imaging , Aortic Valve Stenosis/surgery , Treatment Outcome , Risk Factors
9.
Eur J Cardiothorac Surg ; 63(3)2023 03 01.
Article in English | MEDLINE | ID: mdl-36782361

ABSTRACT

OBJECTIVES: To elucidate the optimal septal reduction therapy for obstructive hypertrophic cardiomyopathy, we conducted a meta-analysis comparing alcohol septal ablation (ASA) and septal myectomy. METHODS: MEDLINE, EMBASE and Cochrane CENTRAL were searched to identify studies investigating the outcomes of ASA and septal myectomy in patients with obstructive hypertrophic cardiomyopathy in January 2023. The primary outcome of interest was all-cause mortality in studies with ≥1 year of follow-up. The secondary outcomes of interest comprised left ventricular outflow tract (LVOT) pressure gradient reduction and reoperations of LVOT. A subgroup analysis of all-cause mortality including studies with follow-up ≥5 years was performed. RESULTS: 27 observational studies were included (15 968 patients). Analysis demonstrated similar all-cause mortality [hazard ratio (HR) (95% confidence interval) (CI) 1.24 (0.88-1.76); P = 0.21; I2 = 56%]. In contrast, ASA was associated with less reduction of LVOT pressure gradient and a reoperation rate [weighted mean difference (95% CI) 11.04 mmHg (5.60-16.48); P < 0.01; I2 = 64%, HR (95% CI) 9.14 (6.55-12.75); P < 0.001; I2 = 0%, respectively]. The subgroup analysis with follow-up ≥5 years revealed higher long-term mortality with ASA [HR (95% CI) 1.50 (1.04-2.15); P = 0.03; I2 = 52%]. CONCLUSIONS: Although both septal reduction therapies were associated with similar all-cause mortality, ASA was associated with a higher rate of reoperation and less reduction of LVOT pressure gradient. Furthermore, all-cause mortality with follow-up ≥5 years showed favourable outcomes with septal myectomy, although the result is only hypothesis-generating given a subgroup analysis.


Subject(s)
Ablation Techniques , Cardiac Surgical Procedures , Cardiomyopathy, Hypertrophic , Humans , Ethanol , Heart Septum/surgery , Treatment Outcome , Cardiomyopathy, Hypertrophic/surgery , Ablation Techniques/adverse effects
10.
Asian Cardiovasc Thorac Ann ; 31(2): 102-114, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36571785

ABSTRACT

BACKGROUND: The optimal nadir temperature for hypothermic circulatory arrest during aortic arch surgery remains unclear. We aimed to assess and compare clinical outcomes of all three temperature strategies (deep, moderate, and mild hypothermia) using a network meta-analysis. METHODS: After literature search with MEDLINE and EMBASE through December 2021, studies comparing clinical outcomes with deep (<20°C), moderate (20-28°C), or mild (>28°C) hypothermic circulatory arrest were included. The outcomes of interest were perioperative mortality, stroke, transient ischemia attack (TIA), acute kidney injury (AKI), postoperative bleeding, operative time, and length of hospital stay. RESULTS: Twenty-four comparative studies were identified, including 6018 patients undergoing aortic arch surgery using hypothermic circulatory arrest (deep: 2,978, moderate: 2,525, and mild: 515). Compared to deep hypothermia, mild and moderate hypothermia were associated with lower mortality (mild vs. deep: odds ratio [OR] 0.50; 95% confidence interval (CI) 0.29-0.87, moderate vs. deep: OR 0.68; 95% CI 0.54-0.86). In addition, mild hypothermia was associated with lower stroke (OR 0.50; 95% CI 0.28-0.89), AKI (OR 0.36; 95% CI 0.15-0.88) and postoperative bleeding (OR 0.55; 95% CI 0.31-0.97) compared to deep hypothermia. There was no significant difference between mild and moderate hypothermia in mortality, AKI or bleeding occurrence, while mild hypothermia was associated with shorter operative time and hospital stay. There was no significant difference in TIA rate among three groups. CONCLUSIONS: Mild hypothermia was associated with overall more favorable clinical outcomes with comparable neurological complications compared to deep hypothermia. Furthermore, considering the shorter operative time and hospital stay compared with moderate hypothermia, mild hypothermia may be warranted when appropriate adjunctive cerebral perfusion is employed.


Subject(s)
Acute Kidney Injury , Hypothermia, Induced , Hypothermia , Ischemic Attack, Transient , Stroke , Humans , Aorta, Thoracic/surgery , Temperature , Network Meta-Analysis , Hypothermia/complications , Ischemic Attack, Transient/complications , Circulatory Arrest, Deep Hypothermia Induced/adverse effects , Stroke/complications , Perfusion/adverse effects , Acute Kidney Injury/diagnosis , Acute Kidney Injury/etiology , Acute Kidney Injury/therapy , Cerebrovascular Circulation , Retrospective Studies , Hypothermia, Induced/adverse effects , Treatment Outcome
11.
Article in English | MEDLINE | ID: mdl-36227647

ABSTRACT

Acute type A aortic dissection is a life-threatening condition that confers significant early perioperative risk but is also associated with late aortic disease progression and the need for reintervention. Recent efforts to improve patient outcomes have focused on improving quality of care and extending treatment in the aortic root and arch to reduce late aortic events. The hybrid arch frozen elephant trunk technique facilitates a more aggressive distal aortic repair that may help mitigate the early and late deleterious effects of persistent false lumen perfusion. However, in the acute and emergency settings, management of the left subclavian artery remains a challenge. We present a step-by-step instructional guide on performing an emergency hybrid arch frozen elephant trunk procedure with emphasis on management of the difficult left subclavian artery. Our case report demonstrates a transthoracic aortoaxillary extra-anatomic bypass of the left axillary artery. We discuss the most important considerations when managing the left subclavian artery in an acute type A aortic dissection. Finally, we detail the benefits and limitations of the transthoracic aortoaxillary extra-anatomic technique and discuss other approaches to left subclavian artery reconstruction.


Subject(s)
Aortic Aneurysm, Thoracic , Aortic Dissection , Blood Vessel Prosthesis Implantation , Aortic Dissection/surgery , Aorta, Thoracic/surgery , Aortic Aneurysm, Thoracic/surgery , Blood Vessel Prosthesis Implantation/methods , Humans , Stents , Treatment Outcome
12.
J Card Surg ; 37(11): 3964-3966, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36116048

ABSTRACT

Surgical treatment of infective endocarditis remains a challenge, with concerns of optimal prosthesis selection and risks of recurrent infection remaining paramount. The pulmonary autograft has unique features which may make it the ideal aortic valve substitute, especially in infectious endocarditis. We describe strategic considerations and technical details in performing a Ross procedure in a young patient with acute aortic valve endocarditis.


Subject(s)
Endocarditis, Bacterial , Endocarditis , Heart Valve Prosthesis Implantation , Pulmonary Valve , Aortic Valve/surgery , Autografts , Endocarditis/surgery , Endocarditis, Bacterial/surgery , Humans , Pulmonary Valve/transplantation , Transplantation, Autologous , Treatment Outcome
13.
Ann Thorac Surg ; 113(4): e275-e278, 2022 04.
Article in English | MEDLINE | ID: mdl-34283955

ABSTRACT

Left atrial-esophageal fistula after radiofrequency ablation for atrial fibrillation is a rare and potentially lethal complication. Although surgical management is associated with improved outcomes, the optimal approach remains to be elucidated. We describe a case of atrial-esophageal fistula treated with a simultaneous repair of the atrium and esophagus via a right thoracotomy with an extrapericardial off-pump approach.


Subject(s)
Atrial Fibrillation , Catheter Ablation , Esophageal Fistula , Atrial Fibrillation/complications , Atrial Fibrillation/surgery , Catheter Ablation/adverse effects , Esophageal Fistula/etiology , Esophageal Fistula/surgery , Heart Atria/surgery , Humans
14.
Cardiovasc Interv Ther ; 37(3): 549-557, 2022 Jul.
Article in English | MEDLINE | ID: mdl-34773568

ABSTRACT

The evidence regarding the impact of cerebral embolic protection devices (EPDs) on outcomes following transcatheter aortic valve replacement (TAVR) is limited. The objective of this study was to evaluate in-hospital outcomes with the use of cerebral EPDs in TAVR. We performed a comprehensive EMBASE and PUBMED search to investigate randomized control studies or propensity score-matched retrospective studies which assessed patients undergoing TAVR with or without EPD up to April 2021. Endpoints of interest were in-hospital mortality, stroke, acute kidney injury, pacemaker implantation, major bleeding, vascular complication, length of stay. Ten studies involving 173,002 patients with EPD (n = 16,898, 9.8%) and those without (n = 156,104, 90.2%) fulfilled the inclusion criteria. The use of EPD was associated with significantly lower risk of in-hospital stroke (odds ratio [95% confidential interval]: 0.64 [0.46; 0.89]), but similar rate of in-hospital mortality (odds ratio [95% confidential interval]: 0.75 [0.54; 1.05]). No differences were observed in acute kidney injury, pacemaker implantation, major bleeding, vascular complication, length of stay. EPD during TAVR was associated with lower in-hospital stroke but did not affect procedural complications and length of stay.


Subject(s)
Acute Kidney Injury , Aortic Valve Stenosis , Embolic Protection Devices , Intracranial Embolism , Stroke , Transcatheter Aortic Valve Replacement , Acute Kidney Injury/epidemiology , Acute Kidney Injury/etiology , Acute Kidney Injury/prevention & control , Aortic Valve/surgery , Aortic Valve Stenosis/complications , Hospitals , Humans , Intracranial Embolism/etiology , Intracranial Embolism/prevention & control , Intracranial Embolism/surgery , Retrospective Studies , Risk Factors , Stroke/epidemiology , Stroke/etiology , Stroke/prevention & control , Transcatheter Aortic Valve Replacement/adverse effects , Treatment Outcome
15.
J Card Surg ; 36(11): 4369-4375, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34472140

ABSTRACT

OBJECTIVE: The optimal harvesting technique of saphenous vein (SVG) in coronary artery bypass grafting (CABG) is still to be elucidated. The present study aimed to compare the methods of SVG harvesting technique, which were open vein harvesting (OVH), endoscopic vein harvesting (EVH), and no-touch vein harvesting (NT), using a network meta-analysis of randomized controlled trials (RCTs), and propensity-score matched (PSM) studies. METHODS: MEDLINE and EMBASE were searched through April 2021 to identify RCTs and PSM studies that investigated the outcomes in patients who underwent CABG with the SVG using one of three methods; OVH, EVH, and NT. The outcomes of interest were all-cause mortality, the rates of revascularization, and graft failure. Risk ratios (RRs) were extracted for the rates of graft failure, and hazard ratios (HRs) were extracted for all-cause mortality and the rates of revascularization. RESULTS: Eligible seven RCT and five PSM studies were identified which enrolled a total of 8111 patients. All-cause mortality was significantly lower in patients with EVH compared with OVH (HR [95% confidence interval (CI)] =0.77 [0.65-0.92], p = .0032). The rates of revascularization were similar among the groups. The rate of graft failures was significantly lower in patients with NT compared with OVH (HR [95% CI] =0.54 [0.32-0.90], p = .019) and with EVH (HR [95% CI] =0.39 [0.17-0.86], p = .023). CONCLUSION: NT vein harvesting is favorable for graft patency, and OVH showed higher all-cause mortality than EVH. Further well-powered RCTs are needed to confirm our findings.


Subject(s)
Coronary Artery Bypass , Saphenous Vein , Endoscopy , Humans , Network Meta-Analysis , Tissue and Organ Harvesting
16.
J Artif Organs ; 24(4): 419-424, 2021 Dec.
Article in English | MEDLINE | ID: mdl-33825101

ABSTRACT

Although the influence of continuous-flow left ventricular assist device (CF-LVAD) support on peripheral circulation has been widely discussed, its monitoring modalities are limited. The aim of this study was to assess the peripheral circulation using the laser speckle flowgraph (LSFG) which can quantitatively measure the ocular blood flow. We implanted a centrifugal CF-LVAD (EVAHEART®; Sun Medical Technology Research Corporation, Nagano, Japan) in five adult goats (body weight 44.5 ± 2.9 kg) under general anesthesia. The waveform of the central retinal artery using the mean blur rate (MBR) for ocular blood velocity and fluctuations as a parameter of pulsatility were obtained before LVAD implantation and after LVAD full-bypass support. The MBR waveform and LSFG fluctuation data were compared with the waveform and pulsatility index of the external carotid artery using an ultrasonic flow meter to evaluate circulatory patterns at different levels. The MBR waveform pattern of the central retinal artery was pulsatile before LVAD implantation and less pulsatile under LVAD full bypass. The fluctuation was 14.7 ± 1.86 before LVAD implantation and 3.85 ± 0.61 under LVAD full bypass (p < 0.01), respectively. The fluctuations of LSFG showed a strong correlation with the pulsatility index of the external carotid artery meaning that similar changes in circulatory pattern were observed at two different levels. Measuring the ocular blood flow using LSFG has potential utility for the assessment of the status of the peripheral circulation and its pulsatility during CF-LVAD.


Subject(s)
Eye/blood supply , Heart-Assist Devices , Regional Blood Flow , Animals , Blood Flow Velocity , Goats , Hemodynamics , Laser-Doppler Flowmetry , Lasers
17.
Artif Organs ; 45(2): 124-134, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32813920

ABSTRACT

We have studied the cardiac beat synchronization (CBS) control for a rotary blood pump (RBP) and revealed that it can promote pulsatility and reduce cardiac load. Besides, patients with LVAD support sometimes suffer from aortic and mitral regurgitation (AR and MR). A control method for the RBP should be validated in wider range of conditions to clarify its benefits and pitfalls prior to clinical application. In this study, we evaluated pulsatility and cardiac load reduction obtained with the CBS control on valvular failure conditions with a mathematical model. Diastolic assist could reduce cardiac load on the left ventricle by decreasing external work of the ventricle even in MR cases while it was not so effective in AR cases. Systolic assist can still promote pulsatility in AR and MR cases; however, aortic valve function should be carefully confirmed since pulse pressure can be wider not due to systolic assist but to AR.


Subject(s)
Aortic Valve Insufficiency/prevention & control , Heart Failure/surgery , Heart-Assist Devices/adverse effects , Mitral Valve Insufficiency/prevention & control , Models, Cardiovascular , Aortic Valve Insufficiency/etiology , Aortic Valve Insufficiency/physiopathology , Blood Pressure/physiology , Diastole/physiology , Heart Failure/physiopathology , Heart Rate/physiology , Heart Ventricles/physiopathology , Humans , Mitral Valve Insufficiency/etiology , Mitral Valve Insufficiency/physiopathology , Pulsatile Flow , Systole/physiology , Ventricular Function, Left/physiology
19.
J Artif Organs ; 22(4): 348-352, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31267351

ABSTRACT

The purpose of this study was to observe and clarify the interventricular dysscynchrony caused by continuous-flow left ventricular assist device (CF-LVAD) support using the conductance method. During CF-LVAD support, the systolic phase of the left ventricle (LV) becomes shorter than that of the right ventricle (RV). Accordingly, timing of the systole and diastole during the cardiac cycle is not synchronous between the LV and RV. In this study, we evaluated this phenomenon in a normal heart model using the adult goat (n = 5, body weight 44.5 ± 2.9 kg). A centrifugal LVAD was implanted under general anesthesia. We inserted the conductance catheter into the RV and LV to obtain the pressure-volume relationship of the two ventricles simultaneously. We defined the dyssynchronous status as the sign (plus or minus) of the LV volume-change opposite to that of RV volume-change. Dyssynchronous phase of the cardiac cycle was observed in 5.6 ± 0.65% of hearts under LVAD pump-off and 25.3 ± 3.3% under LVAD full bypass, respectively (p < 0.05). To the best of our knowledge, this is the first experimental report clarifying interventricular dyssynchrony during CF-LVAD support using the conductance method. Quantification of this phenomenon under various support conditions and assessment of influences on the right ventricular function will be studied in future studies.


Subject(s)
Heart Failure/surgery , Heart-Assist Devices/adverse effects , Ventricular Function, Right/physiology , Animals , Diastole , Disease Models, Animal , Goats , Heart Failure/physiopathology , Heart Ventricles/physiopathology , Systole , Ventricular Dysfunction, Right/etiology , Ventricular Dysfunction, Right/physiopathology
20.
J Artif Organs ; 22(4): 276-285, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31327062

ABSTRACT

We studied a control method of rotary blood pumps (RBPs), which is called as the cardiac beat synchronization (CBS) system. Usually, RBPs operate at constant target rotational speed, meanwhile, the CBS system modulates target speed synchronizing with cardiac beat. We built a computer simulation method to evaluate the CBS system. This simulator acquires a mathematical model of a circulatory system including a RBP and can provide us the theoretical hemodynamics when our control method is applied. We compared theoretical results with experimental ones with the model focusing on both pulsatility and aortic valve (AV) opening interval enhanced by the CBS system. Our simulator could reproduce behavior of the circulatory system whether the RBP is connected or not. Comparison among no RBP, constant assist, systolic assist, and diastolic assist modes indicated that pulsatility is enhanced with systolic assist theoretically. While systolic assist decreased AV opening interval, diastolic assist made it longer than the ones in other control strategies.


Subject(s)
Aortic Valve/physiopathology , Computer Simulation , Heart Rate/physiology , Heart-Assist Devices , Models, Cardiovascular , Diastole , Humans , Pulsatile Flow , Systole
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