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1.
Circ J ; 83(3): 567-575, 2019 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-30745489

RESUMEN

BACKGROUND: The ideal surgical technique for ischemic mitral regurgitation (MR) is controversial. We introduced an extended posterior mitral leaflet (PML) augmentation technique for functional MR with severe tethering, which detached the PML from the annulus almost completely and augmented it with a large 3×6-cm oval pericardial patch. Methods and Results: A total of 17 mitral repairs using the new technique were performed for ischemic MR with no 30-day mortality and 2 hospital deaths. The NYHA class was III in 47% and IV in 13%. The EuroSCORE II was 9.7±4.9. The ring size was 32±1.4 mm. Concomitant coronary bypass was performed in 67% and left ventricular repair in 28%. The mechanism of leaflet closure was evaluated using transthoracic echocardiography in 15 survivors. MR decreased to none or trivial with a significant increase in coaptation length (Pre: 4.6±0.8 mm vs. Post: 9.8±2.5 mm; P<0.001). The PML flexibly moved forward and tightly contacted as if "snuggling up" to the anterior leaflet. There were no late deaths, heart failure readmissions or MR recurrences during follow-up (850±181 days). All patients remained in NYHA I or II. CONCLUSIONS: Extended PML augmentation for ischemic MR showed excellent early results with deep leaflet coaptation through a "snuggling up" phenomenon, which would help prevent late MR recurrence.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos/métodos , Isquemia/etiología , Insuficiencia de la Válvula Mitral/cirugía , Anciano , Procedimientos Quirúrgicos Cardíacos/mortalidad , Procedimientos Quirúrgicos Cardíacos/normas , Ecocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Insuficiencia de la Válvula Mitral/diagnóstico por imagen , Insuficiencia de la Válvula Mitral/mortalidad , Insuficiencia de la Válvula Mitral/patología , Recurrencia , Estudios Retrospectivos , Resultado del Tratamiento
2.
J Artif Organs ; 20(4): 377-380, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28986731

RESUMEN

Venovenous extracorporeal membrane oxygenation is now an established treatment for acute respiratory distress syndrome. However, this treatment remains rare in octogenarians and is associated with poor outcomes. An 81-year-old man with a history of chronic obstructive pulmonary disease and heavy smoking underwent mitral and tricuspid valve repair and the Maze procedure for mitral and tricuspid regurgitation and paroxysmal atrial fibrillation. Although he was extubated the following day, his postoperative course was complicated with pneumonia followed by acute respiratory distress syndrome. He was reintubated on day 7. Ratio of partial pressure of arterial oxygen to fraction of inspired oxygen continuously dropped to less than 100 mmHg, and venovenous extracorporeal membrane oxygenation support was induced on day 18. His lung condition showed slow and steady recovery, and he was successfully weaned from mechanical support on day 44 (total support, 27 days). Bleeding complication from tracheotomy (day 31) due to disseminated intravascular coagulation was successfully managed using recombinant human soluble thrombomodulin. He was ambulatory and discharged to a nursing facility without tracheotomy on day 172. Proper extracorporeal membrane oxygenation management, while challenging to keep the elderly patient away from further complications, saved an 81-year-old patient.


Asunto(s)
Oxigenación por Membrana Extracorpórea , Complicaciones Posoperatorias/terapia , Síndrome de Dificultad Respiratoria/terapia , Anciano de 80 o más Años , Procedimientos Quirúrgicos Cardíacos , Humanos , Masculino , Neumonía/complicaciones , Complicaciones Posoperatorias/etiología , Síndrome de Dificultad Respiratoria/etiología
3.
Ann Vasc Dis ; 13(3): 343-346, 2020 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-33384744

RESUMEN

The J Graft Open Stent Graft (JOSG) is used for the frozen elephant trunk procedure in Japan. We report a 70-year-old male who developed a rapidly progressing distal arch aneurysm caused by a distal stent graft-induced new entry (DSINE) 7 months after the procedure. The JOSG was originally implanted at the curved part of the distal arch. It created its initial DSINE on the greater curve and rapidly "sprang" back in 2 months. Urgent thoracic endovascular aortic repair fixed this serious complication. We should remember such rapid progression of DSINE by JOSG and treat its initial sign earlier.

4.
J Surg Case Rep ; 2020(1): rjz191, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32257100

RESUMEN

The GORE EXCLUDER Iliac Branch Endoprosthesis (IBE) device is designed to seal off a common iliac artery (CIA) aneurysm, preserving the internal iliac artery during endovascular aortic repair. We report the case of an 84-year-old man with isolated saccular right CIA aneurysm (35 mm) and a relatively small terminal aorta (24 mm). The IBE device was successfully placed, and intraoperative angiography revealed no leakage or delay. However, postoperative computed tomography revealed marked compression of the contralateral leg by a bridging component. Although his ankle-brachial index was preserved, its acute occlusion was judged highly possible; we decided to perform preemptive angioplasty. The angiography revealed the stenosis only in the left anterior oblique view, and angioplasty was uneventfully performed. The leg was successfully patent at 1-year follow-up. When compression by IBE and bridging component in the terminal aorta is expected, caution should be preserved at intraoperative angiography following the device deployment.

5.
Ann Thorac Surg ; 109(3): 771-779, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31472135

RESUMEN

BACKGROUND: New guidelines from The Society of Thoracic Surgeons recommend adding surgical ablation as a concomitant procedure for class I indications. We performed the maze procedure for all patients who experienced atrial fibrillation (AF) before cardiac surgery, without surgeon pre-exclusion. METHODS: We retrospectively analyzed 83 patients, aged 71 ± 11 years (22% >80 years), who underwent Cox maze IV for persistent AF between 2014 and 2017. The mean AF duration (AFD) was 6.9 ± 8.6 years and European System for Cardiac Operative Risk Evaluation II was 7.2 ± 6.8. RESULTS: The 30-day mortality was 2.4%. During follow-up (mean, 675 days), the 1-, 2-, and 3-year survival rates were 92%, 86%, and 82%, respectively. No strokes were observed despite a mean CHA2DS2-VASC (Congestive heart failure, Hypertension, Age [≥65 = 1 point, ≥75 = 2 points], Diabetes, and Stroke/transient ischemic attack [2 points], vascular disease, Sex [female = 1 point]) score of 4.1 (expected stroke rate, 4%/y). Twelve patients required a new pacemaker; 56 of 73 survivors (77%) remained AF free. Multivariate logistic regression identified preoperative AFD, f wave size, and mean heart rate per Holter as important risk factors for AF recurrence, with AFD as the most important: 98% of patients with AFD less than 5 years remained AF free. Although the AF-free rate with the AFD of 5 or more years was only 55%, their symptoms improved without heart failure readmission. Concomitant atrial plication was performed more frequently in the group with AFD for 5 or more years, with greater atrial volume reduction and appreciable increases in stroke volume. CONCLUSIONS: The Cox maze IV procedure performed without pre-exclusion showed reasonable survival rates. Although AF recurred in patients with longer AFD, they fared well with substantial increases in stroke volume. Concomitant atrial volume reduction may have contributed to these additional benefits.


Asunto(s)
Fibrilación Atrial/cirugía , Ablación por Catéter/métodos , Sistema de Conducción Cardíaco/fisiopatología , Complicaciones Posoperatorias/epidemiología , Medición de Riesgo/métodos , Anciano , Anciano de 80 o más Años , Fibrilación Atrial/mortalidad , Fibrilación Atrial/fisiopatología , Ecocardiografía , Electrocardiografía , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Japón/epidemiología , Masculino , Complicaciones Posoperatorias/diagnóstico , Radiografía Torácica , Recurrencia , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia/tendencias
6.
Gen Thorac Cardiovasc Surg ; 67(11): 982-986, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30120673

RESUMEN

We present the cases of eight patients (mean age 75 years; EuroSCORE II 17.0 ± 22.0) who underwent post-cardiotomy venovenous extracorporeal membrane oxygenation (ECMO) without heparinization due to serious bleeding. Three liver cirrhosis, two chronic hemodialysis, three redo sternotomy, and two urgent surgery cases were included. Respiratory ECMO Survival Prediction score was - 5.1 ± 4.2 (estimated survival rate: approximately 30%). Mean ECMO duration was 14 days with 9 circuit exchanges. Five patients were weaned from ECMO and three were discharged alive at 90 days (survival 37.5%). There was a case of pump-head thrombosis requiring urgent circuit exchange. All experienced bleeding complications without clinically apparent pulmonary thromboembolism. Disseminated Intravascular Coagulation scores (Pre 1.3 ± 0.8 vs. Post 3.8 ± 1.7; p < 0.05) significantly increased (N = 6). Post-cardiotomy ECMO without heparinization facilitated patient rescue at a reasonable survival rate. However, bleeding complications were still observed. More sophisticated management protocols are warranted.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos/efectos adversos , Contraindicaciones de los Medicamentos , Oxigenación por Membrana Extracorpórea/métodos , Hemorragia/etiología , Anciano , Anciano de 80 o más Años , Anticoagulantes/uso terapéutico , Heparina/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Tasa de Supervivencia
7.
J Cardiol Cases ; 18(3): 99-102, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30279922

RESUMEN

Although surgical left atrial (LA) volume reduction combined with mitral valve surgery and/or surgical ablation for atrial fibrillation has been reported to be effective, its long-term outcomes in the absence of mitral procedure are not well established. A 74-year-old man with two previous sternotomies-the first for pericardiectomy due to constrictive pericarditis and the second for mitral valve replacement with mechanical valve and tricuspid annuloplasty-presented with heart failure and thrombus in his giant left atrium (1291 mL), complicated by cerebral infarction. His electrocardiogram showed rate-controlled persistent atrial fibrillation. His mechanical valve was functioning well. A third atrial volume reduction combined with pulmonary vein isolation, without valve surgery, was performed. The postoperative course was uneventful, and the patient has remained asymptomatic with regular junctional rhythm and without any episodes of thromboembolism or re-dilation of LA (approximately 550 mL). His left ventricular filling improved with end-diastolic volume (96 mL vs 140 mL) and forced vital capacity (2.60 L vs 2.89 L) increased. Both remained relatively constant for 6 years. The combination of atrial volume reduction with pulmonary vein isolation prevented thromboembolism, improved left ventricular filling, and continued to improve symptoms associated with heart failure and respiratory condition for 6 years. .

8.
Jpn J Thorac Cardiovasc Surg ; 54(12): 511-5, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17236652

RESUMEN

OBJECTIVE: Hypoxic perfusion before arrest, an indeterminate period of warm ischemia, and subsequent reperfusion are major causes of cardiac allograft dysfunction in non-heart-beating donors (NHBDs). The present study was undertaken to elucidate the cardioprotective effects of ET(A) receptor antagonist FR139317 for hearts obtained from asphyxiated NHBDs in a canine transplantation model. METHODS: Hypoxic cardiac arrest was induced in 17 donor dogs. FR139317 (10 mg/kg) was given to 7 of the dogs over a period of 10 min before disconnecting the ventilator. The hearts were preserved with FR 139317-supplemented cardioplegic solution (FR group). The remaining 10 did not receive FR 139317 at any time during the experiment (control group). Orthotopic transplantation was performed after a mean myocardial ischemic time of 4h. RESULTS: During the agonal period, the highest systolic pulmonary artery pressure in the FR group was lower than that in the control group (47 +/- 14 vs. 58 +/- 27 mmHg). All animals in the FR group were weaned from cardiopulmonary bypass, whereas only five of the controls were weaned, two of which were identified to have dominant right ventricular failure. After transplantation, recovery rates of the left ventricular end-systolic pressure-volume ratio (E(max)) and the maximum first derivative of pressure measured over time (max dP/dt) were not significantly different between the groups, but recovery rates of the cardiac index, left ventricular minimum dP/dt and exponential time constant of LV relaxation (tau) in the FR group were higher than those in the control group. CONCLUSIONS: The ET(A) receptor antagonist FR 139317 reduced pressure overload on the right ventricle by decreasing the peak pulmonary artery pressure before donor arrest. Cardioprotective effects of this agent for heart transplantation from NHBDs are manifested by preserved diastolic properties of the left ventricle.


Asunto(s)
Asfixia , Azepinas/uso terapéutico , Antagonistas de los Receptores de la Endotelina A , Paro Cardíaco , Trasplante de Corazón , Ventrículos Cardíacos/efectos de los fármacos , Indoles/uso terapéutico , Animales , Perros , Femenino , Masculino , Trasplante Homólogo
9.
Ann Thorac Surg ; 101(5): 1990-2, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27106440

RESUMEN

Pentacuspid pulmonary valve is an extremely rare congenital anomaly. A 71-year-old woman presented with dyspnea on exertion. The preoperative examination showed a large pulmonary artery aneurysm with severe pulmonary regurgitation. The pentacuspid pulmonary valve was an intraoperative finding with four equivalent leaflets and one hypoplastic leaflet. The valve was successfully repaired by use of a bicuspidization technique combined with annuloplasty, and pulmonary artery reduction was performed. Postoperatively, the patient remained asymptomatic with trivial pulmonary regurgitation 1 year later. To our knowledge, this is the first report of a pentacuspid pulmonary valve repair.


Asunto(s)
Aneurisma/cirugía , Anuloplastia de la Válvula Cardíaca/métodos , Arteria Pulmonar/cirugía , Insuficiencia de la Válvula Pulmonar/cirugía , Válvula Pulmonar/anomalías , Válvula Pulmonar/cirugía , Anciano , Aneurisma/complicaciones , Dilatación Patológica/cirugía , Disnea/etiología , Ecocardiografía , Femenino , Humanos , Insuficiencia de la Válvula Pulmonar/diagnóstico por imagen , Insuficiencia de la Válvula Pulmonar/etiología
10.
Circulation ; 108 Suppl 1: II226-9, 2003 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-12970237

RESUMEN

BACKGROUND: We developed a total right ventricular (RV) exclusion procedure for the treatment of isolated congestive RV failure. The objective of the present study was to elucidate the effects of a complete removal of RV volume overload (RVVO) on the surgically created single left ventricle (LV). METHODS AND RESULTS: Three adults (2 arrhythmogenic RV dysplasia, 1 Ebstein) and 5 children (all Ebstein) in NYHA class IV underwent the procedure. The RV free wall was resected from the heart, and the tricuspid orifice was closed. Pulmonary blood supply was obtained by a cavopulmonary connection in 6 patients and a systemic-pulmonary shunt in 2. The LV function was evaluated by 2-dimensional echocardiography 1 month after the surgery. All patients are alive. The paradoxical movement of the interventricular septum and geometry of the LV expressed by its eccentricity (2.1 to 1.2, P<0.01) were normalized after the operation in all 8 patients. LV end-diastolic volumes (59% to 109% of normal value, P<0.01), indexed maximal left atrial area (6.5 to 10.5 cm2/m2, P<0.01), LV ejection fraction (27% to 62%, P<0.01), and cardiac index (2.1 to 3.3 L/min/m2, P<0.05) all significantly increased. CONCLUSIONS: Removal of the RVVO by means of the total RV exclusion procedure provides effective volume loading, restores a cylindrical shape, and improves contractile function of the LV, thus leading to increased systemic output.


Asunto(s)
Insuficiencia Cardíaca/cirugía , Ventrículos Cardíacos/cirugía , Disfunción Ventricular Derecha/cirugía , Adulto , Preescolar , Ecocardiografía Doppler , Femenino , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/fisiopatología , Humanos , Lactante , Masculino , Persona de Mediana Edad , Disfunción Ventricular Derecha/diagnóstico por imagen , Disfunción Ventricular Derecha/fisiopatología , Función Ventricular Izquierda
11.
Circulation ; 106(12 Suppl 1): I198-202, 2002 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-12354733

RESUMEN

BACKGROUND: Insertion of an implantable left ventricular assist device (LVAD) complicated by early right ventricular (RV) failure has a poor prognosis and is largely unpredictable. Prediction of RV failure after LVAD placement would lead to more precise patient selection and optimal device selection. METHODS AND RESULTS: We reviewed data from 245 patients (mean age, 54+/-11 years; 85% male) with 189 HeartMate (77%) and 56 Novacor (23%) LVADs. Ischemic cardiomyopathy predominated (65%), and 29% had dilated cardiomyopathy. Overall, RV assist device (RVAD) support was required after LVAD insertion for 23 patients (9%). We compared clinical and hemodynamic parameters before LVAD insertion between RVAD (n=23) and No-RVAD patients (n=222) to determine preoperative risk factors for severe RV failure. By univariate analysis, female gender, small body surface area, nonischemic etiology, preoperative mechanical ventilation, circulatory support before LVAD insertion, low mean and diastolic pulmonary artery pressures (PAPs), low RV stroke work (RVSW), and low RVSW index (RVSWI) were significantly associated with RVAD use. Elevated PAP and pulmonary vascular resistance were not risk factors. Risk factors by multivariable logistic regression were preoperative circulatory support (odds ratio [OR], 5.3), female gender (OR, 4.5), and nonischemic etiology (OR, 3.3). CONCLUSIONS: The need for circulatory support, female gender, and nonischemic etiology were the most significant predictors for RVAD use after LVAD insertion. Regarding hemodynamics, low PAP and low RVSWI, reflecting low RV contractility, were important parameters. This information may lead to better patient selection for isolated LVAD implantation.


Asunto(s)
Insuficiencia Cardíaca/etiología , Corazón Auxiliar/efectos adversos , Disfunción Ventricular Derecha/etiología , Adolescente , Adulto , Anciano , Femenino , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Hemodinámica , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales , Disfunción Ventricular Derecha/diagnóstico , Disfunción Ventricular Derecha/fisiopatología
12.
Asian Cardiovasc Thorac Ann ; 23(3): 261-6, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25033914

RESUMEN

BACKGROUND: Severe patient-prosthesis mismatch, defined as effective orifice area index ≤0.65 cm(2) m(-2), has demonstrated poor long-term survival after aortic valve replacement. Reported rates of severe mismatch involving the Perimount Magna aortic bioprosthesis range from 4% to 20% in patients with a small annulus. METHODS: Between June 2008 and August 2011, 251 patients (mean age 70.5 ± 10.2 years; mean body surface area 1.55 ± 0.19 m(2)) underwent aortic valve replacement with a Perimount Magna bioprosthesis, with or without concomitant procedures. We performed our procedure with rigorous patient-prosthesis matching to implant a valve appropriately sized to each patient, and carried out annular enlargement when a 19-mm valve did not fit. The bioprosthetic performance was evaluated by transthoracic echocardiography predischarge and at 1 and 2 years after surgery. RESULTS: Overall hospital mortality was 1.6%. Only 5 (2.0%) patients required annular enlargement. The mean follow-up period was 19.1 ± 10.7 months with a 98.4% completion rate. Predischarge data showed a mean effective orifice area index of 1.21 ± 0.20 cm(2) m(-2). Moderate mismatch, defined as effective orifice area index ≤0.85 cm(2) m(-2), developed in 4 (1.6%) patients. None developed severe mismatch. Data at 1 and 2 years showed only two cases of moderate mismatch; neither was severe. CONCLUSIONS: Rigorous patient-prosthesis matching maximized the performance of the Perimount Magna, and no severe mismatch resulted in this Japanese population of aortic valve replacement patients.


Asunto(s)
Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/cirugía , Bioprótesis , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Prótesis Valvulares Cardíacas/efectos adversos , Anciano , Anciano de 80 o más Años , Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/mortalidad , Ecocardiografía , Femenino , Estudios de Seguimiento , Implantación de Prótesis de Válvulas Cardíacas/métodos , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Diseño de Prótesis/métodos , Resultado del Tratamiento
13.
J Thorac Cardiovasc Surg ; 123(3): 544-9, 2002 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11882829

RESUMEN

OBJECTIVE: An animal model of chronic severe heart failure is needed to evaluate new mechanical devices, surgical procedures, and medical therapies. The purpose of this study was to evaluate a unique new model of severe heart failure developed by means of a novel protocol of rapid ventricular pacing. METHODS: Heart failure was induced in 8 mongrel dogs by means of rapid ventricular pacing (230 beats/min) for 4 weeks. After a sham operation, maintenance pacing at a reduced rate (190 beats/min) was continued for another 4 weeks. RESULTS: Left ventricular systolic function was significantly reduced at week 4 and remained low at week 8, including the slope of the end-systolic pressure-volume relationship (2.4 +/- 1.0 vs 0.7 +/- 0.2 vs 0.8 +/- 0.3 mm Hg/mL [baseline vs week 4 vs week 8, respectively]), ejection fraction (63% +/- 5% vs 28% +/- 7% vs 33% +/- 5%), and cardiac output (3.1 +/- 0.7 vs 2.0 +/- 0.3 vs 2.2 +/- 0.7 L/min). Significant ventricular remodeling changes took place with increased ventricular volumes and circumferential wall stress, which were stable between weeks 4 and 8. Serum catecholamine and atrial natriuretic polypeptide levels also increased from baseline but stabilized between weeks 4 and 8. The end-diastolic pressure-volume relationship also showed stable diastolic function between weeks 4 and 8. CONCLUSIONS: Induction pacing at 230 beats/min readily created severe heart failure in all animals, and a new technique of maintenance pacing provided a consistent model of severe heart failure. This model can be used to study a variety of new interventions for heart failure.


Asunto(s)
Estimulación Cardíaca Artificial , Cardiomiopatía Dilatada , Modelos Animales de Enfermedad , Animales , Cardiomiopatía Dilatada/diagnóstico por imagen , Cardiomiopatía Dilatada/fisiopatología , Perros , Ecocardiografía Tridimensional , Hemodinámica , Función Ventricular Izquierda
14.
J Am Soc Echocardiogr ; 16(5): 424-31, 2003 May.
Artículo en Inglés | MEDLINE | ID: mdl-12724650

RESUMEN

BACKGROUND: Doppler tissue echocardiography and color M-mode Doppler flow propagation velocity have proven useful in evaluating cross-sections of patients with left ventricular (LV) dysfunction, but experience with serial changes is limited. PURPOSE AND METHODS: We tested their use by evaluating the temporal changes of LV function in a pacing-induced congestive heart failure model. Rapid ventricular pacing was initiated and maintained in 20 dogs for 4 weeks. Echocardiography was performed at baseline and weekly during brief pacing cessation. RESULTS: With rapid pacing, LV volume significantly increased and ejection fraction (57%-28%), stroke volume (37-18 mL), and mitral annulus systolic velocity (16.1-6.6 cm/s) by Doppler tissue echocardiography significantly decreased, with ejection fraction and mitral annulus systolic velocity closely correlated (r = 0.706, P <.0001). In contrast to the mitral inflow velocities, mitral annulus early diastolic velocity decreased steadily (12.3-7.3 cm/s) resulting in a dramatic decrease in mitral annulus early/late (1.22-0.57) diastolic velocity with no tendency toward pseudonormalization. The color M-mode Doppler flow propagation velocity also showed significant steady decrease (57-24 cm/s) throughout the pacing period. Multiple regression analysis chose mitral annulus systolic velocity (r = 0.895, P <.0001) and propagation velocity (r = 0.782, P <.0001) for the most important factor predicting LV systolic and diastolic function, respectively. CONCLUSIONS: Doppler tissue echocardiography and color M-mode Doppler flow could evaluate the serial deterioration in LV dysfunction throughout the pacing period. These were more useful in quantifying progressive LV dysfunction than conventional ehocardiographic techniques, and were probably relatively independent of preload. These techniques could be suitable for longitudinal evaluation in addition to the cross-sectional study.


Asunto(s)
Ecocardiografía Doppler en Color , Ecocardiografía Doppler , Insuficiencia Cardíaca/diagnóstico por imagen , Disfunción Ventricular Izquierda/diagnóstico por imagen , Animales , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Perros , Insuficiencia Cardíaca/fisiopatología , Análisis de Regresión
15.
J Am Soc Echocardiogr ; 17(5): 411-7, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15122179

RESUMEN

We assessed the effects of implantation of Myosplint (Myocor, Maple Grove, Minn), a device that changes left ventricular (LV) cross-sectional shape from circular to bilobar, on regional LV function. A total of 10 open-chest dogs with tachycardia-induced cardiomyopathy were studied before and after Myosplint implantation. LV cross-sectional epicardial echocardiography at the papillary muscle level was performed along with acquisition of hemodynamic data. LV normalized thickening, fractional thickening, end-diastolic thickness, and end-diastolic curvatures were calculated for 10 LV segments. Myosplint implantation did not affect LV hemodynamics, but decreased average end-diastolic curvature (P <.0001) and increased its segmental heterogeneity (P <.0001). There was no change in average fractional thickening, whereas normalized thickening increased (P =.05). In contrast, segmental heterogeneity of both normalized and fractional thickening increased (P =.02 and P =.01, respectively). Structural modeling confirmed that Myosplint implantation increases regional stress heterogeneity and curvature heterogeneity. LV cross-sectional shape markedly affects regional LV performance.


Asunto(s)
Cardiomiopatías/diagnóstico por imagen , Cardiomiopatías/fisiopatología , Corazón Auxiliar , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/fisiopatología , Animales , Cardiomiopatías/patología , Perros , Modelos Cardiovasculares , Ultrasonografía , Disfunción Ventricular Izquierda/patología
16.
ASAIO J ; 48(3): 268-71, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12059001

RESUMEN

We have reported that device based left ventricular (LV) shape change, accomplished by Myosplint, improved LV systolic function by three-dimensional echocardiography (3-D echo). However, evaluation of this device using the pressure-volume relationship is still important. This study was conducted to validate the use of conductance technology for this evaluation in shape-changed hearts. An ex vivo study using excised ovine hearts (n = 11) and an in vivo study using a canine pacing-induced heart failure model (n = 11) were performed. Three Myosplints were implanted. Before and after the shape changes, volumes measured by a conductance catheter were compared with volumes measured by the amount of saline in the ex vivo study or by 3-D echo in the in vivo study. The conductance volumes were linearly correlated with the saline volumes (r2 = 0.961+/-0.046; p < 0.0001) in the ex vivo study and with 3-D echo volumes (r2 = 0.757+/-0.220; p < 0.0001) in the in vivo study. The conductance volumes were linearly correlated with LV volumes even in the shape-changed hearts. This technology can be used to evaluate pressure-volume loops in the shape-changed hearts as long as the conductance volume is calibrated by a reliable method.


Asunto(s)
Insuficiencia Cardíaca/terapia , Corazón Auxiliar , Hipertrofia Ventricular Izquierda/terapia , Animales , Cateterismo Cardíaco , Volumen Cardíaco , Perros , Conductividad Eléctrica , Ovinos , Función Ventricular Izquierda
17.
ASAIO J ; 48(6): 606-11, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12455770

RESUMEN

The purpose of this study was to evaluate the in vitro responses to preload and afterload of our total artificial heart (TAH), the MagScrew TAH. The TAH consists of two blood pumps and a control logic, developed at the Cleveland Clinic, OH, and the MagScrew actuator and its electronic control system, developed by Foster-Miller Technologies, Inc., Albany, NY. Tests were performed on a mock circulatory loop, using water as a test fluid. Preload sensitivity of the Mag-Screw TAH demonstrated a Frank-Starling response to preload in automatic mode. A peak flow of 10 L/min was obtained, with a left atrial pressure of 13 mm Hg. The relationship between right atrial pressure and left atrial pressure was well balanced when tested with a left bronchial shunt flow of 5% and a range of pulmonary artery and aortic pressures. With respect to afterload response, the left pump showed a relatively low sensitivity, which allowed the pump to maintain perfusion over a wide range of aortic pressures. The right pump, on the other hand, was much more sensitive to pulmonary artery pressure, which provided a measure of protection against pulmonary congestion. The very effective physiologic response of the MagScrew TAH is believed to result from employment of a left master, alternating ejection control logic, high inherent sensitivity of the blood pumps to atrial pressure, a lower effective stroke volume for the right pump, and a scaling of right side motor ejection voltage to 80% of that used for the left side ejection.


Asunto(s)
Corazón Artificial , Corazón/fisiología , Aorta/fisiología , Presión Sanguínea/fisiología , Atrios Cardíacos , Técnicas In Vitro , Diseño de Prótesis , Arteria Pulmonar/fisiología , Volumen Sistólico/fisiología , Presión Venosa/fisiología
18.
ASAIO J ; 48(3): 222-5, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12058993

RESUMEN

The purpose of this study was to evaluate the in vivo pump performance of our total artificial heart (TAH), the "MagScrew TAH." The TAH consists of a blood pump and control logic developed at the Cleveland Clinic and the MagScrew actuator and electronic control system developed by Foster-Miller Technologies, Inc. (Albany, NY). MagScrew TAH implantation was performed in two calves. Study durations were 50 and 5 days. The causes of termination were prosthetic valve endocarditis in one case and cable failure in the other. Mean left pump flow ranged from 8.0 to 9.7 L/min, with left atrial pressure of 3.0 to 16.0 mm Hg. Preload sensitivity of the MagScrew TAH demonstrated a Frank-Starling response to preload in automatic mode. The relationship between right and left atrial pressure was well balanced. Mean arterial pressure and mean pulmonary artery pressure were maintained within physiologic ranges over study duration. There were no signs of bleeding, hemolysis, or organ failure. The MagScrew TAH showed physiologic pump performance, and hemodynamics were well maintained without any organ failure. Further development testing will bring the MagScrew TAH to the point of preclinical readiness testing.


Asunto(s)
Corazón Artificial , Animales , Bovinos , Hemodinámica , Cuidados Posoperatorios
19.
ASAIO J ; 48(3): 249-52, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12058998

RESUMEN

The Cleveland Clinic CorAide left ventricular assist system consists of a permanently implantable centrifugal pump in which the rotating assembly is completely suspended and noncontacting. A series of chronic animal in vivo studies were conducted to evaluate the biologic effects of CorAide circulatory support without the use of anticoagulation therapy. The CorAide pump was implanted in six calves (five calves for 21 to 32 days and one calf for 95 days). The first five calves received intravenous heparin during the early postoperative periods (2-7 days). Heparin administration was then discontinued and no other anticoagulant drugs were used for the duration of the experiments. The last calf did not receive any anticoagulant except for a bolus dose of heparin (200 U/kg) during surgery. Hemodynamics were stable in all six calves, with a mean pump flow of 5.6+/-1.2 L/min and mean arterial pressure of 100+/-4 mm Hg. The blood pump surfaces were clean of thrombus in all six calves. Significant findings at autopsy were limited to one case of renal infarction. There was no incidence of mechanical failure, bleeding, or device infection. The CorAide pump can be safely run with minimal or no anticoagulant therapy.


Asunto(s)
Anticoagulantes/farmacología , Corazón Auxiliar , Animales , Bovinos , Hemodinámica , Heparina/farmacología , Humanos
20.
Jpn J Thorac Cardiovasc Surg ; 52(1): 26-9, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-14760988

RESUMEN

It has been reported by several authors that a right thoracotomy for mitral valve surgery can be useful after previous coronary aortery bypass grafting (CABG). A 76-year-old man with mitral valve regurgitation after previous CABG underwent mitral valve replacement with some modified techniques. Cardiopulmonary bypass was established with right brachial artery cannulation and right femoral venous cannulation with the aid of vacuum-assisted venous drainage. Ventricular fibrillation (VF) was induced by rapid pacing of the ventricle, and mitral valve replacement was performed under perfused VF with moderate hypothermia. The patient's postoperative course was uneventful. This method appears to be a safe and easy alternative mitral valve surgery for complicated cases of this type.


Asunto(s)
Puente de Arteria Coronaria , Prótesis Valvulares Cardíacas , Insuficiencia de la Válvula Mitral/cirugía , Toracotomía/métodos , Anciano , Arteria Braquial , Drenaje/métodos , Humanos , Hipotermia Inducida , Masculino , Procedimientos Quirúrgicos Mínimamente Invasivos , Válvula Mitral/cirugía , Fibrilación Ventricular
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