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1.
Cardiovasc Res ; 40(3): 580-90, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10070500

RESUMEN

CONDENSED ABSTRACT: We analyzed actomyosin cross-bridge kinetics in human atrial and ventricular muscle strip preparations by using sinusoidal length changes from 0.1 to 60 Hz. The minimum stiffness frequency was higher in atrial than in ventricular human myocardium and lower in failing than in non-failing left ventricular human myocardium. beta-Adrenergic stimulation increased the minimum stiffness frequency by 18 +/- 3% (p < 0.05). Cross-bridge kinetics are temperature-dependent, with a Q10 of at least 2.7. BACKGROUND: Dynamic stiffness measurements have revealed acute and chronic alterations of actomyosin cross-bridge kinetics in cardiac muscles of a variety of different animal species. We studied dynamic stiffness in right atrial and left ventricular preparations of non-failing and failing human hearts and tested the influence of the temperature and beta-adrenergic stimulation on cross-bridge kinetics. METHODS AND RESULTS: Muscle strips were prepared from right atria and left ventricles from human non-failing and failing hearts. After withdrawal of calcium, steady contracture tension was induced by the addition of 1.5 mM barium chloride. Sinusoidal length oscillations of 1% muscle length were applied, with a frequency spectrum of between 0.1 and 60 Hz. Dynamic stiffness was calculated from the length change and the corresponding force response amplitude. The specific minimum stiffness frequency, which indicates the interaction between cross-bridge recruitment and cross-bridge cycling dynamics, was analyzed for each condition: (1) The minimum stiffness frequency was 0.78 +/- 0.04 Hz in left ventricular myocardium and 2.80 +/- 0.31 Hz in right atrial myocardium (p < 0.01) at 27 degrees C. (2) The minimum stiffness frequency was 41% higher in non-failing compared to failing left ventricular human myocardium. (3) Over a wide range of experimental temperatures, the minimum stiffness frequency changed, with a Q10 of at least 2.7. (4) beta-Adrenergic stimulation significantly (p < 0.05) increased the minimum stiffness to 18 +/- 3% higher frequencies and significantly (p < 0.05) lowered contracture tension by 7 +/- 1%. CONCLUSIONS: The contractility of human heart muscle is not only regulated by excitation-contraction coupling but also by modulation of intrinsic properties of the actomyosin system. Acute and chronic alterations of cross-bridge kinetics have been demonstrated, which play a significant role in the physiology and pathophysiology of the human heart.


Asunto(s)
Actomiosina/fisiología , Cardiomiopatía Dilatada/fisiopatología , Corazón/fisiopatología , Agonistas Adrenérgicos beta/farmacología , Compuestos de Bario/farmacología , Temperatura Corporal , Cloruros/farmacología , Elasticidad/efectos de los fármacos , Corazón/efectos de los fármacos , Atrios Cardíacos , Ventrículos Cardíacos , Humanos , Técnicas In Vitro , Isoproterenol/farmacología , Estimulación Química
2.
Cardiovasc Res ; 37(1): 46-57, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9539857

RESUMEN

BACKGROUND: For reasons of simplicity, studies on isolated human myocardium have been conducted using exclusively isometric contractions, although positive inotropic interventions may differently influence force development, extent of shortening and myocardial work performance. We investigated human left ventricular failing and non-failing preparations comparing isometric versus isotonic, i.e., shortening contractions. RESULTS: (1) When muscle length is increased from 90% to 100% lMAX, peak developed force increases by 36% and 43% (p < 0.05) in non-failing and failing human left ventricular myocardium, respectively. Maximum performed work increases similarly in non-failing but decreases in failing myocardium. It can be shown that this discrepancy is due to significantly higher resting tension and does not present an insufficient intrinsic shortening capacity in failing myocardium. (2) When stimulation rate is increased from 0.5 to 2.0 Hz, isometric force increases significantly by 59% in non-failing and decreases by 27% in failing myocardium, whereas maximum performed work increases by 98% and decreases by 46%, respectively. (3) Pharmacological positive inotropic interventions by 7.2 mM calcium (n = 9), 3 x 10(-8) M isoproterenol (n = 7), 3 x 10(-8) M ouabain (n = 5), and 10(-5) M EMD 57033 (n = 3) equally increased force development and extent of shortening: When the fractional effect on shortening (y) was correlated to the fractional effect on force (x), the following linear regression equation was obtained: y = 0.91x + 0.26 (r = 0.86; p < 0.001). CONCLUSIONS: The data presented are of clinical and pharmacological importance: (1) The Frank-Starling mechanism is demonstrated to be existent in the failing human myocardium regarding both isometric force developed and maximum work performed. (2) Both force-frequency relations and--to a greater extent--work-frequency relations are reversed in failing human myocardium. (3) Independent of the pharmacological mode of action, positive inotropic compounds increase developed isometric force to the same extent as isotonic shortening and therefore potentiate maximum performed work.


Asunto(s)
Cardiomiopatía Dilatada/fisiopatología , Contracción Miocárdica/efectos de los fármacos , Función Ventricular Izquierda/fisiología , Adolescente , Adulto , Anciano , Calcio/farmacología , Cardiomiopatía Dilatada/patología , Cardiotónicos/farmacología , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Isoproterenol/farmacología , Persona de Mediana Edad , Ouabaína/farmacología , Quinolinas/farmacología , Análisis de Regresión , Estimulación Química , Tiadiazinas/farmacología
3.
Transplantation ; 66(9): 1163-7, 1998 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-9825812

RESUMEN

BACKGROUND: The current shortage of donor organs, combined with an increasing demand for cardiac allografts, means that extended donor criteria are becoming more and more accepted. The use of cardiac allografts for transplantation from donors after acute poisoning is still under discussion; few data are currently available in the medical literature. We describe our experience with 19 orthotopic heart transplant recipients of organs from donors after acute intoxication with different agents. METHODS: Between March 1989 and December 1997, 883 orthotopic heart transplantations were performed at our transplant unit. Within this group, we accepted donor hearts after ethanol intoxication (n=1), benzodiazepine (n=1), alkylphosphate (E 605) in combination with beta-blocker intoxication (n=1), carbon monoxide poisoning (n=5), digitalis (n=1), digitalis/glibenclamide (n=1), chlormethiazole (n=1), propoxyphene (n=1), alkylphosphate (E 605) (n=1), insulin (n=2), neprobamate/ thiocyacide/flurazepam (n=1), paracetamol (n=1), carbamazepine (n=1), and cyanide (n=1) intoxication. At the time of organ explantation, hemodynamic data were available from all patients. RESULTS: Early mortality in this group was 11%; cumulative survival after 5 years was 74%. CONCLUSIONS: Based on our limited experience, cardiac allografts from donors exposed to different kinds of poisons can be transplanted in selected cases. If the donor organ is not hemodynamically compromised, showing regular filling pressures on low or mild inotropic support just before explantation, and if there are no electrocardiographic changes in combination with elevation of the transaminases, cardiac allograft transplantation seems to be a safe and life-saving procedure.


Asunto(s)
Trasplante de Corazón/fisiología , Trasplante de Corazón/estadística & datos numéricos , Hemodinámica , Intoxicación/sangre , Donantes de Tejidos , Estudios de Seguimiento , Humanos , Tasa de Supervivencia , Obtención de Tejidos y Órganos , Trasplante Homólogo
4.
J Thorac Cardiovasc Surg ; 119(3): 596-600, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10694622

RESUMEN

OBJECTIVE: The Thoratec ventricular assist device (Thoratec Laboratories, Pleasanton, Calif) is widely accepted for univentricular and biventricular support in patients with various indications. The aim of this study is to describe our experience with implantation of the Thoratec ventricular assist device in more than 100 patients. METHODS: From March 1992 to June 1998, 114 patients (98 men and 16 women; mean age, 47.9 years) received the Thoratec ventricular assist device for a mean duration of 44.9 days. The patients were divided into 3 groups. Group 1 included 84 patients in whom the system was applied as a bridge-to-transplant procedure. Group 2 included 17 patients with postcardiotomy cardiogenic shock, and group 3 included 13 patients with cardiogenic shock of other causes. RESULTS: Sixty-eight percent of patients in group 1 survived to transplantation with a posttransplant survival of 88%. The only independent risk factor affecting survival was age more than 60 years. Survivals in groups 2 and 3 were 47% and 31%, respectively. Main complications in all groups were bleeding, multiple organ failure, liver failure, sepsis, and neurologic disorders. CONCLUSIONS: The Thoratec ventricular assist device has proved to be a reliable device for bridge to transplantation and postcardiotomy support. Further studies are required on patient selection and on patient and device management to reduce the incidence of complications in these patient populations.


Asunto(s)
Corazón Auxiliar , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Diseño de Prótesis , Tasa de Supervivencia
5.
Ann Thorac Surg ; 61(1): 314-6, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8561596

RESUMEN

BACKGROUND: In spite of modern cardiac surgical techniques, severe cardiogenic shock not responding to pharmacologic therapy and intraaortic balloon pumping develops in about 0.2% to 1.2% of patients undergoing cardiac operations. METHODS: From September 1987 to September 1994, 184 patients were supported with different mechanical circulatory support systems. Nine patients with postcardiotomy cardiogenic shock were supported with the Thoratec ventricular assist device. Four patients suffered early postcardiotomy cardiogenic shock, and 5 patients suffered late postcardiotomy cardiogenic shock. In 6 patients the Thoratec device was applied exclusively, in 2 patients both Bio-Medicus and Thoratec, and in 1 patient both ABIOMED and Thoratec devices were used. Duration of support ranged from 5 to 46 days with a mean duration of 15 days. RESULTS: Four patients (44%) survived and were discharged. Main complications and causes of death were multiple organ failure and sepsis. CONCLUSIONS: The results justify the use of Thoratec assist device in patients with severe preoperative cardiogenic shock.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos/efectos adversos , Corazón Auxiliar , Choque Cardiogénico/terapia , Adulto , Anciano , Puente de Arteria Coronaria/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Choque Cardiogénico/etiología
6.
Ann Thorac Surg ; 59(2 Suppl): S56-62; discussion S63, 1995 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7840701

RESUMEN

From September 1987 to February 1994, we treated 147 patients ranging between 11 and 82 years old with different mechanical circulatory support systems. The applied devices were the Bio-Medicus centrifugal pump in 61 patients, the Abiomed BVS System 5000 in 49 patients, the Thoratec ventricular assist device in 42 patients, and the Novacor left ventricular assist device in 7 patients. On the basis of indication for mechanical circulatory support, the patients were divided into three groups: group 1 consisted of 72 patients with postcardiotomy cardiogenic shock; group 2, 50 patients in whom mechanical support was used as a bridge to cardiac transplantation; and group 3 (miscellaneous), 25 patients in cardiogenic shock resulting from acute myocardial infarction (n = 14), acute fulminant myocarditis (n = 3), primary graft failure (n = 2), right heart failure after heart transplantation (n = 3), and acute rejection (n = 3). Time of support ranged from 1 hour to 97 days (mean duration, 10.8 days). Seventy-five patients (51%) were discharged from the hospital. The best survival rate was achieved in group 2 with 72%, followed by group 1 with 44% and then group 3 with 28%. The most frequent complications in group 1 were bleeding (44%), multiple-organ failure (24%), neurologic disorders (18%), and acute renal failure (15%). In group 2, the major complications were bleeding (34%) and cerebrovascular disorders (22%) and in group 3, multiple-organ failure and sepsis (60%) and bleeding (32%).


Asunto(s)
Cardiopatías/terapia , Corazón Auxiliar , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
7.
J Psychosom Res ; 38(5): 403-8, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7965929

RESUMEN

Orthotopic heart transplantation has been established as a routine clinical operation. In this study, we were interested in: (a) how patients cope emotionally with the situation pre- and postsurgically, especially with regard to anxiety and depression; and (b) whether the patient's perceived locus of control is related to emotional adjustment before and after heart transplantation. Twenty patients who were on the waiting list for heart transplantation with highest priority provided complete psychological questionnaires presurgically and 20 days after surgery when intensive care was no longer required. During the waiting period, patients rated high on depression, state and trait anxiety in comparison with healthy references while ratings on perceived locus of control scales were within the norm ranges. After surgery, heart transplant patients experienced significantly less state/trait anxiety and depression reaching levels which were no longer statistically different from health references. While postsurgical ratings of anxiety (state and trait) and depression were not significantly correlated with presurgical ratings, both were closely related to ratings of locus of control. Belief in powerful others was positively correlated with pre- and postsurgical anxiety and depression. Chance control orientation was related only to presurgical emotional disturbances. It can be concluded that emotional adjustment after heart transplantation is more likely to be predicted by presurgical ratings of locus of control than by presurgical emotional adjustment.


Asunto(s)
Adaptación Psicológica , Trasplante de Corazón/psicología , Control Interno-Externo , Rol del Enfermo , Adulto , Ansiedad/psicología , Depresión/psicología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Inventario de Personalidad , Complicaciones Posoperatorias/psicología
8.
Eur J Cardiothorac Surg ; 11 Suppl: S1-4, 1997 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9271173

RESUMEN

Advanced coronary artery disease (CAD) and ischemic cardiomyopathy with elevated pulmonary artery pressures are criteria of a severe illness. In selected cases surgical revascularization has proved beneficial in terms of survival, reduction of morbidity and lowering the frequency of angina pectoris [6] in numerous studies over the past 25 years. But most of the earlier publications concentrated on patients with angina pectoris (AP) as a dominant symptom. Patients without AP but with predominant signs of congestive heart failure were largely excluded. This has changed recently [1-3,7,8,10,12,16,18] with the advent of the concept of hibernating myocardium. This term is defined as the presence of persistent myocardial and left ventricular dysfunction at rest due to reduced regional coronary blood flow that can be partially or completely restored to normal by myocardial revascularization [5,19]. Salvage of viable myocardium by successful revascularization improves left ventricular dysfunction. Diagnosis of hibernating myocardium is crucial because it does not leave the patient with chronic heart failure a candidate only for cardiac transplantation. Instead, these patients' left ventricular dysfunction is potentially reversible following revascularization by coronary bypass surgery. Furthermore we face a critical shortage of donor organs and extending waiting lists for possible transplant candidates. Following the start of the heart transplantation (HTX) program at our institution more than 690 operations were performed until September 1995. We screened more than 1600 patients for their eligibility as cardiac transplant recipients or for other forms of treatment. In this group of patients it has always been our policy to revascularize rather than transplant whenever possible.


Asunto(s)
Trasplante de Corazón , Isquemia Miocárdica/cirugía , Revascularización Miocárdica , Adulto , Anciano , Femenino , Hemodinámica , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/mortalidad , Isquemia Miocárdica/fisiopatología , Selección de Paciente , Complicaciones Posoperatorias , Disfunción Ventricular Izquierda/cirugía
9.
Eur J Cardiothorac Surg ; 11 Suppl: S51-3, 1997 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9271182

RESUMEN

From March 1993 to August 1995, 33 patients received implantable VAD systems at our center. Nineteen patients received the wearable Novacor LVAS and 14 patients the TCI HeartMate device. Both systems enable the patients to be mobilized very quickly and some of them even do not require critical care after a few days. In our series 17 patients (eight Novacor, nine TCI) could be transferred to the normal floor. The wearable electrically driven Novacor system opens the opportunity of sending patients out of hospital. Since July 1994 we have referred five patients to a rehabilitation center, and six patients were sent home, three of them for more than 70 days. A number of factors are necessary to prepare the patient for being discharged. One of the most important things is to guarantee ambulatory patient care and to find an easy way for effective home monitoring. Our experience has shown that discharging these patients means giving them a maximum in quality of life and decreasing the costs by more than 50% in comparison to a stay in hospital for the whole time. Our results are encouraging to improve this strategy in the future.


Asunto(s)
Atención Ambulatoria , Corazón Auxiliar , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Electricidad , Femenino , Predicción , Personal de Salud/educación , Trasplante de Corazón , Humanos , Masculino , Persona de Mediana Edad , Alta del Paciente , Calidad de Vida
10.
Int J Artif Organs ; 15(12): 715-21, 1992 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1493947

RESUMEN

Between January 1988 and January 1992, 65 patients (pts) had a ventricle assist device (VAD) inserted in our clinic. In 24 pts a VAD was applied because of primarily unsuccessful weaning from cardiopulmonary bypass (Group A). In a further 24 pts (Group B) a VAD was installed for the therapy of refractive cardiogenic shock (CS) after initially successful cardiac surgery (n = 21) and after acute myocardial infarction (n = 3). Twelve pts were bridged to heart transplantation (Group C) and five had a VAD inserted for various other reasons (Group D). In 36 (55.4%) of the total 65 pts a nonpulsatile VAD (Biomedicus 540) was used: 10 in Group A; 20 in B, 3 in C and 3 in D. In 29 pts (44.6%) a pulsatile VAD (Abiomed BVS 5000) was used: 14 in Group A, 4 in B, 9 in C and 2 in D. Weaning rate and long-term survival rates were 50% and 46% respectively in Group A and 38% and 42% in Group B. Seven pts from Group C were transplanted and six are long-term survivors. Two pts (40%) in Group D were discharged from hospital. Major postoperative complications were bleeding (46%), thromboembolism (14%), multiple organ failure (11%), renal failure (11%), arterial embolism (4.6%), sepsis (3%). The results indicate that application of a VAD can be recommended in pts with postcardiotomy CS to allow recovery of cardiac function and in pts with irreversible ventricular damage as bridging to HTX.


Asunto(s)
Corazón Auxiliar , Choque Cardiogénico/terapia , Adulto , Anciano , Anciano de 80 o más Años , Dopamina/uso terapéutico , Epinefrina/uso terapéutico , Femenino , Trasplante de Corazón , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Tasa de Supervivencia
11.
Int J Artif Organs ; 17(9): 492-8, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7890438

RESUMEN

Since we started using ventricular assist devices (VAD) in July 1987 up to August 1993, 63 of 15,650 (0.4%) patients (pts) who underwent open heart surgery were supported postoperatively by VAD at out institution. Forty-three were male and 20 female, mean age 55.5 years. In 49 pts coronary artery bypass grafting (CABG), in 8 pts valve surgery, in 3 pts combined CABG and valve surgery and in 3 pts corrective procedures for congenital heart disease were performed. Perioperative myocardial infarction was the most frequent indication (73%). In 37 of the 63 pts (58.7%) a centrifugal (Biomedicus pump (group A) was used and in 26 pts (41.3%) a pulsatile Abiomed BVS 5000 (group B). Fourteen of 37 pts (38%) in group A were weaned from the VAD and all of them were discharged. Twenty-three pts were unable to be weaned and 19 of these pts died. The remaining 4 pts were transplanted successfully and subsequently 3 died and 1 was discharged. In all, 15 pts (39%) were long-term survivors. Sixteen of 26 pts (62%) in group B were weaned from VAD and 13 (50%) of them were discharged of whom 3 died. Ten patients were unable to be weaned and 7 of these died. The remaining 3 pts were transplanted successfully. In all, 16 pts (61.5%) were long-term survivors. The shorter the interval between beginning resuscitation and application of VAD the better the outcome. Younger age, VAD installation in OR, support time between 2 and 7 days and Abiomed pump, influence the survival rate positively.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Gasto Cardíaco Bajo/terapia , Procedimientos Quirúrgicos Cardíacos , Corazón Auxiliar/normas , Complicaciones Posoperatorias/terapia , Adulto , Anciano , Anciano de 80 o más Años , Gasto Cardíaco Bajo/etiología , Gasto Cardíaco Bajo/mortalidad , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Puente de Arteria Coronaria , Femenino , Paro Cardíaco/patología , Paro Cardíaco/terapia , Cardiopatías Congénitas/cirugía , Trasplante de Corazón , Válvulas Cardíacas/cirugía , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Infarto del Miocardio/patología , Infarto del Miocardio/terapia , Complicaciones Posoperatorias/mortalidad , Tasa de Supervivencia
14.
Z Orthop Ihre Grenzgeb ; 120(2): 151-7, 1982 Apr.
Artículo en Alemán | MEDLINE | ID: mdl-7102055

RESUMEN

The incidence of clinically and roentgenologically manifest Kienböck disease was checked on the basis of a thorough analysis of 85 patients suffering from the condition. Apart from sex distribution and age at onset, particular importance was attached to certain "constitutional factors". The fact in all bilaterally affected patients the ulnar was smaller than average at the wrist, and the advanced signs of arthrosis were radiologically demonstrated in 81.8% of the patients, once again confirms that certain constitutional factors play a decisive role in the Pathogenesis of Kienböch disease. Their importance for treatment, and also for possible assessments for insurance purpose, is emphasized.


Asunto(s)
Hueso Semilunar/patología , Osteocondritis/etiología , Adolescente , Adulto , Factores de Edad , Femenino , Alemania Occidental , Humanos , Masculino , Osteocondritis/epidemiología , Osteocondritis/patología , Factores Sexuales
15.
Artículo en Alemán | MEDLINE | ID: mdl-9498097

RESUMEN

We report on a 21-year old patient who nearly drowned in cold water under inexplicable circumstances. About 1/2 hour later he was found with cardiac arrest. Immediate cardiopulmonary resuscitation remained unsuccessfully but was continued. After transportation to the nearest hospital a core temperature of 26.1 degrees C was recorded. A team of our hospital arrived 2 1/2 hours after start of cardiopulmonary resuscitation. After introducing a femo-femoral bypass the patient was rapidly rewarmed and oxygenated using a portable extracorporeal circulation and membrane oxygenation. Defibrillation succeeded at a core temperature of 34.4 degrees C. A severe ARDS developed the same day which was successfully treated by membrane oxygenation. 41 days later the patient left the hospital fully recovered.


Asunto(s)
Circulación Extracorporea , Oxigenación por Membrana Extracorpórea , Ahogamiento Inminente/terapia , Resucitación/métodos , Adulto , Temperatura Corporal , Cardioversión Eléctrica , Humanos , Hipotermia , Masculino , Ahogamiento Inminente/complicaciones , Síndrome de Dificultad Respiratoria/etiología , Síndrome de Dificultad Respiratoria/terapia , Resucitación/instrumentación
16.
Circ Res ; 75(3): 473-82, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8062421

RESUMEN

In various mammalian species, shapes of action potentials vary within the cardiac wall because of differences in transient outward current (Ito). A prominent Ito exists in human ventricular myocytes, but cells have not been separated according to their original localization. Human ventricular myocytes were isolated from separated subepicardial and subendocardial tissue, and regional variations in Ito were studied. Ito was larger in subepicardial than subendocardial cells. Current density at +60 mV was 7.9 +/- 0.7 pA/pF (n = 28) in subepicardial cells and 2.3 +/- 0.3 pA/pF (n = 16) in subendocardial cells. When cells from explanted failing and nonfailing donor hearts were compared, Ito was not different in subepicardial cells; however, it was larger in subendocardial cells from nonfailing hearts. The potential of half-maximal activation (V0.5) was more positive in subendocardial cells (+25.6 +/- 3.5 mV, n = 15) than in subepicardial cells (+9.2 +/- 1.8 mV, n = 28). There was no difference in V0.5 between cells from failing and nonfailing hearts. Ito inactivation was similar in all cell types and independent of membrane depolarization (time constant [tau] = approximately 60 milliseconds at 22 degrees C). The potential of half-maximal steady-state inactivation was similar in all cell types. Recovery from inactivation of Ito was fast in subepicardial cells at -100 mV (tau = 24 +/- 4 milliseconds, n = 6), exceeding control values transiently (overshoot), and slow at -40 mV without overshoot (tau = 638 +/- 91 milliseconds, n = 6). In subendocardial cells, Ito recovered at -100 mV with a fast phase (tau = 25 milliseconds) and a slow phase (tau = 328 milliseconds), and recovery was not complete after 6 seconds at -100 mV. In conclusion, regional differences in Ito between subepicardial and subendocardial cells may have clinical implications with respect to rhythmic disturbance during heart failure.


Asunto(s)
Corazón/fisiología , Adolescente , Adulto , Cadmio/farmacología , Cloruro de Cadmio , Cardiomiopatías/fisiopatología , Separación Celular , Células Cultivadas , Cloruros/farmacología , Endocardio , Femenino , Corazón/fisiopatología , Humanos , Masculino , Potenciales de la Membrana/efectos de los fármacos , Persona de Mediana Edad , Factores de Tiempo , Donantes de Tejidos
17.
Z Kardiol ; 87(11): 900-5, 1998 Nov.
Artículo en Alemán | MEDLINE | ID: mdl-9885184

RESUMEN

Papillary fibroelastomas are rare benign tumors of the heart. We report about two cases in which these tumors do not--as characteristically--arise from a heart valve but originate from the free wall of the left ventricle. In the case of a 74-year-old woman with signs of a cerebral ischemia in the vascular system of the A. cerebri posterior, the tumor was resected transaortically. At a 67-year-old patient with symptoms of instable angina pectoris and increasing dyspnoea echocardiography or coronary angiography showed an aortic stenosis III degrees, a coronary artery disease as well as a tumor within the region of the apex of the left ventricle. Beside a fourfold aortocoronary venous bypass and an aortic valve replacement tumor excision via left ventriculotomy was carried out. In the diagnostics of intracardiac tumors transthoracic and transesophageal echocardiography provide the methods of choice to visualize quickly and noninvasively the extent, mobility, and origin of the tumor. Considering the systemic thromboembolic potential with the high risk of cerebrovascular respectively neurological symptoms total surgical tumor excision is clearly indicated.


Asunto(s)
Fibroma/diagnóstico , Neoplasias Cardíacas/diagnóstico , Enfermedades de las Válvulas Cardíacas/diagnóstico , Anciano , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/patología , Diagnóstico Diferencial , Electrocardiografía , Femenino , Fibroma/patología , Neoplasias Cardíacas/patología , Enfermedades de las Válvulas Cardíacas/patología , Humanos , Masculino
18.
Circulation ; 90(3): 1141-53, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8087924

RESUMEN

BACKGROUND: Serotonin may contract human large coronary arteries through two 5-hydroxytryptamine (5-HT) receptors, 5-HT1-like and 5-HT2. These 5-HT1-like receptors resemble both cloned 5-HT1D receptor subtypes, 5-HT1D alpha and 5-HT 1D beta. Although these subtypes have similar pharmacology, 5-HT1D beta receptors appear to have lower affinity for ketanserin than 5-HT1D alpha receptors. We assessed the relative participation of 5-HT1-like and 5-HT2 receptors and attempted to identify whether vasoconstrictor 5-HT1-like receptors are 5-HT1D alpha or 5-HT1D beta. METHODS AND RESULTS: Epicardial coronary arteries were dissected from the hearts of 29 patients (including 1 healthy (donor) undergoing heart transplant operation. Endothelium-denuded strips were set up to contract at 37 degrees C. To assess the relative contributions of 5-HT1-like and 5-HT2 receptors, we blocked the latter with ketanserin (0.1 to 1.0 mumol/L) and ketanserin-resistant receptors with methiothepin (0.1 mumol/L). Concentration-effect curves for 5-HT, in the absence and presence of ketanserin, were analyzed by using a model for two receptor subtypes. The fractional contributions of 5-HT1-like and 5-HT2 receptors to the maximum effect of 5-HT, f1 and f2, were estimated in arteries from 28 patients: f1 (0.71 +/- 0.20, mean +/- SD) was significantly larger than f2 (0.29 +/- 0.20) (P < .0001). Using [3H]-serotonin to label transfected and expressed receptors, we verified that ketanserin has lower affinity for 5-HT1D beta (pKi [-log Ki, mol/L] less than 5.0) than for 5-HT1D alpha (pKi = 7.1 +/- 0.1) receptors. A concentration of ketanserin (1 mumol/L) that would occupy more than 90% of 5-HT1D alpha receptors failed to block 5-HT-induced contractions (4 patients). The 5-HT1-like receptor stimulant sumatriptan evoked maximal contractions that matched f1 and was equipotent with 5-HT through 5-HT1-like receptors (8 patients). No systematic influence of disease, atheroma, or therapy on f1 and f2 was detected. CONCLUSIONS: Coronary artery contractile 5-HT1-like receptors resemble cloned 5-HT1D beta receptors and predominate over 5-HT2 receptors in mediating serotonin-evoked contractions. Sumatriptan contracts coronary arteries as a full agonist through 5-HT1-like receptors.


Asunto(s)
Vasos Coronarios/efectos de los fármacos , Receptores de Serotonina/fisiología , Serotonina/farmacología , Vasoconstricción/fisiología , Adulto , Arteriosclerosis/fisiopatología , Unión Competitiva , Cardiomiopatía Dilatada/fisiopatología , Clonación Molecular , Enfermedad Coronaria/fisiopatología , Femenino , Humanos , Técnicas In Vitro , Ketanserina/farmacología , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/fisiopatología , Receptores de Serotonina/clasificación , Receptores de Serotonina/metabolismo , Antagonistas de la Serotonina/farmacología , Sumatriptán/farmacología , Vasoconstricción/efectos de los fármacos
19.
Artif Organs ; 20(8): 959-63, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8853815

RESUMEN

Advances in medical technology have made it possible to use emergency femoro-femoral bypass (FFB) for transport of hemodynamically unstable patients. In this study, we report on our experience of transport of patients with refractory heart failure by a special mobile mechanical circulatory support team (MMCST) using an intraaortic balloon pump (IABP) or FFB. A total of 22 patients (14 men, 8 women) were supported by the MMCST and transported to our clinic for further diagnostic or therapeutic procedures. The diagnoses in 12 patients was acute myocardial infarction, in 7 patients, dilatative cardiomyopathy (DCM), and in 3 patients, acute fulminant myocarditis. In 15 cases, FFB was implanted (5 in combination with IABP), and in 5 cases, IABP only was implanted. Two patients received maximal dosages of catecholamines. After arrival at our clinic, 11 patients received implants of a more sophisticated support system. From the myocardial infarction group, 3 patients received coronary artery bypass grafting, 1 patient received percutaneous transluminal coronary angioplasty, and 1 patient received heart transplantation as final therapy. In the myocarditis and DCM groups, 7 patients underwent heart transplantation. Finally, 11 patients (50%) survived, and 11 patients died of multiorgan failure or septicemia.


Asunto(s)
Insuficiencia Cardíaca/fisiopatología , Hemodinámica/fisiología , Sistemas de Manutención de la Vida/normas , Transporte de Pacientes/normas , Adulto , Ambulancias/normas , Cardiomiopatía Dilatada/mortalidad , Cardiomiopatía Dilatada/terapia , Puente Cardiopulmonar , Femenino , Insuficiencia Cardíaca/mortalidad , Humanos , Unidades de Cuidados Intensivos , Contrapulsador Intraaórtico , Masculino , Persona de Mediana Edad , Infarto del Miocardio/mortalidad , Infarto del Miocardio/terapia , Miocarditis/mortalidad , Miocarditis/terapia
20.
Artif Organs ; 20(8): 964-70, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8853816

RESUMEN

Although the natural history of acute myocarditis leads to complete recovery in the majority of patients, rapid and irreversible cardiac decompensation resulting in death is known to occur. One possible therapy to improve the poor prognosis of this patient group may be the implantation of circulatory support systems that allow myocardial recovery or bridging to heart transplantation. Therapeutic protocols have been suggested, but clinical experiences in this area are few. In this paper we report on our clinical experiences in cardiogenic shock after acute fulminant myocarditis using different types of circulatory support systems. Three different systems were used: a biomedicus centrifugal pump as a ventricular assist device (VAD) or femoro-femoral bypass (FFB) including oxygenator; Abiomed BVS 5000, and Thoratec ventricular assist device. Hemodynamic criteria for implantation of support systems were cardiac index < 2.0 L/min/m2. SVR = 1000 dyne-s-cm-5, central venous pressure (CVP) or left atrial pressure (LAP) > 20 mm Hg, and urine output < 20 ml/h despite maximal pharmacological therapy. Age total of 5 patients (mean age 29 years, range 15-55 years) in cardiogenic shock after acute fulminant myocarditis were included. Two patients initially were supported for stabilization and transportation from an outside hospital by FFB. Both patients died after a support time of 24 h because of multiorgan failure or neurological disorders after longer periods of resuscitation in the referral hospital. The third patient (55 years) received the Biomedicus pump as CVAD. Myocardial function recovered after a support time of 120 h, and the patient could be weaned. Unfortunately, 2 days after weaning, he developed malignant arrhythmias and died. The 2 remaining patients (15 years and 27 years) with diagnosis of acute fulminant virus myocarditis were supported by biventricular assist device (1 x Thoratec/111 days, 1 x Abiomed/7 days). During the entire time of support, there were no signs of myocardial recovery. The patients were accepted for the heart transplantation (HTX) program. In both cases, HTXs were performed without any complication. The postoperative course was uneventful. The results of mechanical circulatory support in patients with acute fulminant myocarditis are encouraging and justify the resources.


Asunto(s)
Cardiomiopatías/terapia , Puente Cardiopulmonar , Trasplante de Corazón , Corazón Auxiliar , Miocarditis/terapia , Adulto , Cardiomiopatías/cirugía , Femenino , Humanos , Masculino , Insuficiencia Multiorgánica/mortalidad , Miocarditis/cirugía , Complicaciones Posoperatorias , Choque Cardiogénico/terapia , Transporte de Pacientes/normas
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