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1.
Aging Clin Exp Res ; 34(5): 1073-1080, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34751924

RESUMEN

BACKGROUND: Implantable cardioverter-defibrillator (ICD) therapy is well established for secondary prevention, but studies on the efficacy and safety in elderly patients are still lacking. This retrospective study compared the outcome after ICD implantation between octogenarians and other age groups. METHODS: Data were obtained from a local ICD registry. Patients who received ICD implantation for secondary prevention at our department were included. All-cause mortality, appropriate ICD therapy and acute adverse events requiring surgical intervention were compared between different age groups. RESULTS: 519 patients were enrolled, 34 of whom were aged ≥ 80 years. During the median follow-up of 35 months after ICD implantation 129 patients (annual mortality rate 5.0%) had died, including 16 patients aged ≥ 80 years (annual mortality rate 9.4%). The mortality rate of patients aged ≥ 80 years was significantly higher than that of patients aged ≤ 69 years (p < 0.001), but similar to that of patients aged 70-79 years. Age at the time of ICD implantation was an independent predictor of all-cause mortality (p < 0.001). 29.7% of patients had appropriate ICD therapy with no difference between age groups. Acute adverse events leading to surgical intervention were low (n = 13) and not age-related. CONCLUSION: Age is an independent predictor of mortality after ICD implantation for secondary prevention. Mortality rates did not differ significantly between octogenarians and other elderly aged 70-79 years. Appropriate ICD therapy and acute adverse events leading to surgical intervention were not age-related. Implantable cardioverter-defibrillator therapy for secondary prevention seems to be an effective and safe treatment modality in octogenarians.


Asunto(s)
Muerte Súbita Cardíaca , Desfibriladores Implantables , Anciano , Anciano de 80 o más Años , Muerte Súbita Cardíaca/etiología , Muerte Súbita Cardíaca/prevención & control , Humanos , Octogenarios , Prevención Primaria , Estudios Retrospectivos , Factores de Riesgo , Prevención Secundaria , Resultado del Tratamiento
2.
Eur Heart J ; 41(34): 3255-3268, 2020 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-32484517

RESUMEN

AIMS: Takotsubo syndrome (TTS) is an acute heart failure syndrome, which shares many features with acute coronary syndrome (ACS). Although TTS was initially described with angiographically normal coronary arteries, smaller studies recently indicated a potential coexistence of coronary artery disease (CAD) in TTS patients. This study aimed to determine the coexistence, features, and prognostic role of CAD in a large cohort of patients with TTS. METHODS AND RESULTS: Coronary anatomy and CAD were studied in patients diagnosed with TTS. Inclusion criteria were compliance with the International Takotsubo Diagnostic Criteria for TTS, and availability of original coronary angiographies with ventriculography performed during the acute phase. Exclusion criteria were missing views, poor quality of angiography loops, and angiography without ventriculography. A total of 1016 TTS patients were studied. Of those, 23.0% had obstructive CAD, 41.2% had non-obstructive CAD, and 35.7% had angiographically normal coronary arteries. A total of 47 patients (4.6%) underwent percutaneous coronary intervention, and 3 patients had acute and 8 had chronic coronary artery occlusion concomitant with TTS, respectively. The presence of CAD was associated with increased incidence of shock, ventilation, and death from any cause. After adjusting for confounders, the presence of obstructive CAD was associated with mortality at 30 days. Takotsubo syndrome patients with obstructive CAD were at comparable risk for shock and death and nearly at twice the risk for ventilation compared to an age- and sex-matched ACS cohort. CONCLUSIONS: Coronary artery disease frequently coexists in TTS patients, presents with the whole spectrum of coronary pathology including acute coronary occlusion, and is associated with adverse outcome. TRIAL REGISTRATION: ClinicalTrials.gov number: NCT01947621.


Asunto(s)
Síndrome Coronario Agudo , Enfermedad de la Arteria Coronaria , Cardiomiopatía de Takotsubo , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/complicaciones , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Humanos , Incidencia , Cardiomiopatía de Takotsubo/complicaciones , Cardiomiopatía de Takotsubo/epidemiología
3.
Circ J ; 84(3): 404-410, 2020 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-32023574

RESUMEN

BACKGROUND: We recently demonstrated that the acute reconnection rate detected with adenosine provocation test (APT) was significantly lower after pulmonary vein isolation (PVI) with visually guided laser balloon ablation (VGLB) than with RF ablation (RF). We evaluated the recurrence rate of atrial arrhythmias at 12 months after VGLB vs. RF and the significance of APT results for the outcome.Methods and Results:Fifty patients with paroxysmal AF were randomized to either RF or VGLB ablation in a 1 : 1 fashion. After PVI each PV underwent an APT. All patients underwent a 3-day Holter and clinical follow-up every 3 months. Significantly less PVs reconnected during APT in the VGLB-arm (10 PV (10.8%) vs. 29 PV (30.9%); P=0.001). Significantly less patients had a recurrence of atrial arrhythmia in the VGLB-arm (3 vs. 9; P=0.047). In the VGLB-arm no recurrence was seen in those patients with a negative APT (negative predictive value (NPV)=100%). Only 3 of the 8 patients with a positive APT in the VGLB-arm had a recurrence (positive PV (PPV)=37%). Recurrences in the RF-arm were seen in 3 patients with positive APT as well as in 6 patients with negative APT (PPV=18% and NPV=33%). CONCLUSIONS: There was significantly less recurrence of atrial arrhythmias at 12 months after PVI with VGLB. A negative APT after PVI with VGBL predicted freedom from AF with a very high NPV meaning that the high acute efficiency of the VGLB persisted long term.


Asunto(s)
Adenosina/administración & dosificación , Fibrilación Atrial/cirugía , Ablación por Catéter , Técnicas Electrofisiológicas Cardíacas , Frecuencia Cardíaca , Terapia por Láser , Venas Pulmonares/cirugía , Potenciales de Acción , Anciano , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/fisiopatología , Ablación por Catéter/efectos adversos , Electrocardiografía Ambulatoria , Femenino , Alemania , Humanos , Terapia por Láser/efectos adversos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Venas Pulmonares/fisiopatología , Recurrencia , Reoperación , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
4.
Biomedicines ; 12(5)2024 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-38790998

RESUMEN

Background: Postoperative de novo atrial fibrillation (POAF) is one of the most frequently encountered complications following cardiac surgery. Despite the identification of several risk factors, the link between sleep-disordered breathing (SDB) and POAF has barely been examined. The objective of this prospective observational study was to determine whether severe SDB is associated with POAF in patients after elective coronary artery bypass grafting (CABG) surgery. Study design and methods: The incidence and preoperative predictors of in-hospital POAF were assessed in 272 patients undergoing CABG surgery at the University Medical Center Regensburg (Germany). In-hospital POAF was detected by continuous telemetry-ECG monitoring and 12-lead resting ECGs within the first seven postoperative days. POAF that occurred after hospital discharge within 60 days post CABG surgery was classified as post-hospital POAF and was ascertained by standardized phone interviews together with the patients' medical files, including routinely performed Holter-ECG monitoring at 60 days post CABG surgery. The night before surgery, portable SDB monitoring was used to assess the presence and type of severe SDB, defined by an apnea-hypopnea index ≥ 30/h. Results: The incidence of in-hospital POAF was significantly higher in patients with severe SDB compared to those without severe SDB (30% vs. 15%, p = 0.009). Patients with severe SDB suffered significantly more often from POAF at 60 days post CABG surgery compared to patients without severe SDB (14% vs. 5%, p = 0.042). Multivariable logistic regression analysis showed that severe SDB (odds ratio, OR [95% confidence interval, CI]: 2.23 [1.08; 4.61], p = 0.030), age ≥ 65 years (2.17 [1.04; 4.53], p = 0.038), and diabetes mellitus (2.27 [1.15; 4.48], p = 0.018) were significantly associated with in-hospital POAF. After additional adjustment for heart failure, the association between sleep apnea and postoperative atrial fibrillation was attenuated (1.99 [0.92; 4.31], p = 0.081). Conclusions: Amongst established risk factors, severe SDB was significantly associated with in-hospital POAF in patients undergoing CABG surgery. Whether SDB contributes to POAF independently of heart failure and whether risk for POAF may be alleviated by proper treatment of SDB merits further investigation.

5.
J Cardiovasc Dev Dis ; 10(3)2023 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-36975862

RESUMEN

BACKGROUND: Pulmonary vein (PV) reconnection is the major cause of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). The probability of reconnection is higher if the primary lesion is not sufficiently effective, which can be unmasked with an adenosine provocation test (APT). High-power short-duration radiofrequency energy (HPSD) guided with ablation index (AI) and the third generation of the visually guided laser balloon (VGLB) are new methods for PVI. METHODS: A total of 70 participants (35 in each group) who underwent a PVI with either AI-guided HPSD (50 W; AI 500 for the anterior and 400 for the posterior wall, respectively) or VGLB ablation were included in this observational pilot trial. Twenty minutes after each PVI, an APT was performed. The primary endpoint was the event-free survival from AF after three years. RESULTS: A total of 137 (100%) PVs in the HPSD arm and 131 PVs (98.5%) in the VGLB arm were initially successfully isolated (p = 0.24). The overall procedure duration was similar in both arms (155 ± 39 in HPSD vs. 175 ± 58 min in VGLB, p = 0.191). Fluoroscopy time, left atrial dwelling time and duration from the first to the last ablation were longer in the VGLB arm (23 ± 8 vs. 12 ± 3 min, p < 0.001; 157 (111-185) vs. 134 (104-154) min, p = 0.049; 92(59-108) vs. 72 (43-85) min, p = 0.010). A total of 127 (93%) in the HPSD arm and 126 (95%) PVs in the VGLB arm remained isolated after APT (p = 0.34). The primary endpoint was met 1107 ± 68 days after ablation in 71% vs. 66% in the VGLB and HPSD arms, respectively (p = 0.65). CONCLUSIONS: HPSD and VGLB did not differ with respect to long-term outcome of PVI. A large, randomized study should be conducted to compare clinical outcomes with respect to these new ablation techniques.

6.
Eur J Med Res ; 27(1): 234, 2022 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-36348435

RESUMEN

PURPOSE: The current study investigated whether the changes in patient care in times of the COVID-19 pandemic, especially the reduction of in-person visits, would result in a deterioration of the arrhythmic and clinical condition of patients with an implantable cardioverter defibrillator (ICD) and remote patient monitoring. METHODS: Data were obtained from a local ICD registry. 140 patients who received ICD implantation at our department and had remote patient monitoring were included. The number of patients with ventricular arrhythmias, appropriate ICD therapy, the number of visits to our outpatient clinic and hospitalization due to acute coronary syndrome, stroke or heart failure were compared during three time intervals of the COVID-19 pandemic (first (LD1) and second (LD2) national lockdown in Germany and the time after the first lockdown (postLD1)) and a time interval 1 year before the pandemic began (preCOV). Each time interval was 49 days long. RESULTS: Patients had significantly fewer visits to our outpatient clinic during LD1 (n = 13), postLD1 (n = 22) and LD2 (n = 23) compared to the time interval before the pandemic (n = 43, each p ≤ 0.05). The number of patients with sustained ventricular arrhythmias, appropriate ICD therapy and clinical events showed no significant difference during the time intervals of the COVID-19 pandemic and the time interval 1 year prior. CONCLUSIONS: The lockdown measures necessary to reduce the risk of infection during the COVID-19 pandemic, led to a reduction of in-person patient visits, but did not result in a deterioration of the arrhythmic and clinical condition of ICD patients with remote patient monitoring.


Asunto(s)
COVID-19 , Desfibriladores Implantables , Humanos , Pandemias , COVID-19/epidemiología , Control de Enfermedades Transmisibles , Arritmias Cardíacas/epidemiología , Arritmias Cardíacas/terapia , Monitoreo Fisiológico
7.
JAMA Cardiol ; 7(5): 494-503, 2022 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-35353118

RESUMEN

Importance: Machine learning algorithms enable the automatic classification of cardiovascular diseases based on raw cardiac ultrasound imaging data. However, the utility of machine learning in distinguishing between takotsubo syndrome (TTS) and acute myocardial infarction (AMI) has not been studied. Objectives: To assess the utility of machine learning systems for automatic discrimination of TTS and AMI. Design, Settings, and Participants: This cohort study included clinical data and transthoracic echocardiogram results of patients with AMI from the Zurich Acute Coronary Syndrome Registry and patients with TTS obtained from 7 cardiovascular centers in the International Takotsubo Registry. Data from the validation cohort were obtained from April 2011 to February 2017. Data from the training cohort were obtained from March 2017 to May 2019. Data were analyzed from September 2019 to June 2021. Exposure: Transthoracic echocardiograms of 224 patients with TTS and 224 patients with AMI were analyzed. Main Outcomes and Measures: Area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity of the machine learning system evaluated on an independent data set and 4 practicing cardiologists for comparison. Echocardiography videos of 228 patients were used in the development and training of a deep learning model. The performance of the automated echocardiogram video analysis method was evaluated on an independent data set consisting of 220 patients. Data were matched according to age, sex, and ST-segment elevation/non-ST-segment elevation (1 patient with AMI for each patient with TTS). Predictions were compared with echocardiographic-based interpretations from 4 practicing cardiologists in terms of sensitivity, specificity, and AUC calculated from confidence scores concerning their binary diagnosis. Results: In this cohort study, apical 2-chamber and 4-chamber echocardiographic views of 110 patients with TTS (mean [SD] age, 68.4 [12.1] years; 103 [90.4%] were female) and 110 patients with AMI (mean [SD] age, 69.1 [12.2] years; 103 [90.4%] were female) from an independent data set were evaluated. This approach achieved a mean (SD) AUC of 0.79 (0.01) with an overall accuracy of 74.8 (0.7%). In comparison, cardiologists achieved a mean (SD) AUC of 0.71 (0.03) and accuracy of 64.4 (3.5%) on the same data set. In a subanalysis based on 61 patients with apical TTS and 56 patients with AMI due to occlusion of the left anterior descending coronary artery, the model achieved a mean (SD) AUC score of 0.84 (0.01) and an accuracy of 78.6 (1.6%), outperforming the 4 practicing cardiologists (mean [SD] AUC, 0.72 [0.02]) and accuracy of 66.9 (2.8%). Conclusions and Relevance: In this cohort study, a real-time system for fully automated interpretation of echocardiogram videos was established and trained to differentiate TTS from AMI. While this system was more accurate than cardiologists in echocardiography-based disease classification, further studies are warranted for clinical application.


Asunto(s)
Infarto del Miocardio , Cardiomiopatía de Takotsubo , Anciano , Inteligencia Artificial , Estudios de Cohortes , Ecocardiografía , Femenino , Humanos , Masculino , Infarto del Miocardio/diagnóstico por imagen , Cardiomiopatía de Takotsubo/diagnóstico por imagen
8.
Cardiol J ; 28(5): 663-670, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32207843

RESUMEN

BACKGROUND: Application of high power radiofrequency (RF) energy for a short duration (HPSD) to isolate pulmonary vein (PV) is an emerging technique. But power and duration settings are very different across different centers. Moreover, despite encouraging preclinical and clinical data, studies measuring acute effectiveness of various HPSD settings are limited. METHODS: Twenty-five consecutive patients with symptomatic atrial fibrillation (AF) were treated with pulmonary vein isolation (PVI) using HPSD. PVI was performed with a contact force catheter (Thermocool SF Smart-Touch) and Carto 3 System. The following parameters were used: energy output 50 W, target temperature 43°C, irrigation 15 mL/min, targeted contact force of > 10 g. RF energy was applied for 6-10 s. Required minimal interlesion distance was 4 mm. Twenty minutes after each successful PVI adenosine provocation test (APT) was performed by administrating 18 mg adenosine to unmask dormant PV conduction. RESULTS: All PVs (100 PVs) were successfully isolated. RF lesions needed per patient were 131 ± 41, the average duration for each RF application was 8.1 ± 1.7 s. Procedure time was 138 ± 21 min and average of total RF energy duration was 16.3 ± 5.2 min and average amount of RF energy was 48209 ± 12808 W. APT application time after PVI was 31.1 ± 8.3 min for the left sided PVs and 22.2 ± 4.6 min (p = 0.005) for the right sided PVs. APT was transiently positive in 18 PVs (18%) in 8 (32%) patients. CONCLUSIONS: Pulmonary vein isolation with high power for 6-10 s is feasible and shortens the procedure and ablation duration. However, acute effectiveness of the HPSD seems to be lower than expected. Further studies combining other ablation parameters are needed to improve this promising technique.


Asunto(s)
Fibrilación Atrial , Ablación por Catéter , Venas Pulmonares , Adenosina , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/cirugía , Humanos , Venas Pulmonares/cirugía , Recurrencia , Resultado del Tratamiento
9.
Int Orthop ; 34(8): 1145-51, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19813012

RESUMEN

In a prospective clinical study, 59 patients with anteromedial osteoarthritis of the knee (61 knee joints) underwent minimally invasive medial Oxford unicompartmental arthroplasty phase 3. Clinical and radiographic examinations of 56 knees were carried out at five (4-7) years. American Knee Society (AKS) scores improved from mean 45.5 (20-80) points (knee score) and 55 (15-100) points (function score) before surgery to 90 (30-100) points in both scores after surgery. The position of each implant was determined on screened radiographs using an image intensifier. The implant position was analysed according to the Oxford X-ray rating system. We evaluated nine measures, and there was no detectable correlation between implant position and clinical result. However, long-term studies are needed before it is possible to elaborate an evidence-based guideline on positioning.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/métodos , Articulación de la Rodilla/diagnóstico por imagen , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Complicaciones Posoperatorias/diagnóstico por imagen , Anciano , Artroplastia de Reemplazo de Rodilla/efectos adversos , Desviación Ósea/diagnóstico por imagen , Desviación Ósea/etiología , Femenino , Fémur/diagnóstico por imagen , Humanos , Articulación de la Rodilla/fisiopatología , Articulación de la Rodilla/cirugía , Prótesis de la Rodilla , Masculino , Persona de Mediana Edad , Osteoartritis de la Rodilla/cirugía , Dolor Postoperatorio , Complicaciones Posoperatorias/etiología , Estudios Prospectivos , Radiografía , Rango del Movimiento Articular , Tibia/diagnóstico por imagen , Resultado del Tratamiento
10.
Int Orthop ; 34(3): 335-9, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19387644

RESUMEN

Osteoarthritis (OA) secondary to dislocation and dysplasia is a common problem in patients with cerebral palsy. The purpose of this study was to evaluate the results of total hip replacement (THR) in ambulatory patients with cerebral palsy. Eighteen total hip arthroplasties were performed in 16 ambulatory patients with cerebral palsy. The patient's mean age at surgery was 42 +/- 8 years (range 32-58 years), and the mean follow-up was 10 +/- 6 years (range 2-18 years). Data were obtained by a standardised telephone interview. There was a significant postoperative reduction in pain on the NAS (narrative analogue scale) from 8.4 preoperatively to 1.1 postoperatively (p = 0.002). At follow-up no stem had been revised. Three cups were revised for aseptic loosening at two and six years, and one cup was revised for recurrent dislocation of the hip. One hip was revised for infection 12 years after the index surgery. One hip dislocated (three months postoperatively) and was treated by closed reduction. In ambulatory patients with cerebral palsy and secondary osteoarthritis of the hip THR can provide long-term pain relief and improved function. The rate of long term complications was moderate in this series; however, the dislocation rate was higher than in standard OA cases.


Asunto(s)
Artroplastia de Reemplazo de Cadera/métodos , Parálisis Cerebral/cirugía , Osteoartritis de la Cadera/cirugía , Adulto , Artroplastia de Reemplazo de Cadera/rehabilitación , Parálisis Cerebral/complicaciones , Parálisis Cerebral/fisiopatología , Femenino , Luxación de la Cadera/etiología , Prótesis de Cadera , Humanos , Entrevistas como Asunto , Masculino , Persona de Mediana Edad , Osteoartritis de la Cadera/etiología , Osteoartritis de la Cadera/fisiopatología , Dimensión del Dolor , Complicaciones Posoperatorias , Falla de Prótesis , Rango del Movimiento Articular , Recuperación de la Función , Reoperación , Factores de Tiempo , Resultado del Tratamiento
11.
Int Orthop ; 33(6): 1585-90, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19219432

RESUMEN

The aim of the study was to determine whether the incidence of radiolucencies can be reduced using pulsed lavage before cementing the tibia in unicompartmental knee arthroplasty (UKA). We prospectively studied a consecutive series of 112 cemented Oxford UKA in 100 patients in two centres. In group A (n = 56) pulsed lavage and in group B (n = 56) conventional syringe lavage was used to clean the cancellous bone. The same standardised cementing technique was applied in all cases. At a minimum follow-up of one year patients were evaluated clinically and screened radiographs were obtained. The cement bone interface under the tibial plateau was divided into four zones and evaluated for the presence of radiolucent lines. All radiographs were evaluated (n = 112), and radiolucencies in all four zones were found in two cases in group A (4%) and in 12 cases in group B (22%) (p = 0.0149). Cement penetration showed a median of 2.6 mm (group A) and 1.5 mm (group B) (p < 0.0001). We recommend the routine use of pulsed lavage in Oxford UKA to reduce the incidence of radiolucency and to improve long-term fixation.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/métodos , Cementación/métodos , Irrigación Terapéutica/métodos , Tibia/diagnóstico por imagen , Anciano , Anciano de 80 o más Años , Cementos para Huesos , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis de la Rodilla/cirugía , Estudios Prospectivos , Radiografía , Resultado del Tratamiento
12.
Eur J Pharmacol ; 622(1-3): 7-14, 2009 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-19751721

RESUMEN

Cardiac glycosides inhibit the Na(+),K(+)-ATPase and are used for the treatment of symptomatic heart failure and atrial fibrillation. In human heart three isoforms of Na(+),K(+)-ATPase are expressed: alpha(1)beta(1), alpha(2)beta(1) and alpha(3)beta(1). It is unknown, if clinically used cardiac glycosides differ in isoform specific affinities, and if the isoforms have specific subcellular localization in human cardiac myocytes. Human Na(+),K(+)-ATPase isoforms alpha(1)beta(1), alpha(2)beta(1) and alpha(3)beta(1) were expressed in yeast which has no endogenous Na(+),K(+)-ATPase. Isoform specific affinities of digoxin, digitoxin, beta-acetyldigoxin, methyldigoxin and ouabain were assessed in [(3)H]-ouabain binding assays in the absence or presence of K(+) (each n=5). The subcellular localizations of the Na(+),K(+)-ATPase isoforms were investigated in isolated human atrial cardiomyocytes by immunohistochemistry. In the absence of K(+), methyldigoxin (alpha(1)>alpha(3)>alpha(2)) and ouabain (alpha(1)=alpha(3)>alpha(2)) showed distinct isoform specific affinities, while for digoxin, digitoxin and beta-acetyldigoxin no differences were found. In the presence of K(+), also digoxin (alpha(2)=alpha(3)>alpha(1)) and beta-acetyldigoxin (alpha(1)>alpha(3)) had isoform specificities. A comparison between the cardiac glycosides demonstrated highly different affinity profiles for the isoforms. Immunohistochemistry showed that all three isoforms are located in the plasma membrane and in intracellular membranes, but only alpha(1)beta(1) and alpha(2)beta(1) are located in the T-tubuli. Cardiac glycosides show distinct isoform specific affinities and different affinity profiles to Na(+),K(+)-ATPase isoforms which have different subcellular localizations in human cardiomyocytes. Thus, in contrast to current notion, different cardiac glycoside agents may significantly differ in their pharmacological profile which could be of hitherto unknown clinical relevance.


Asunto(s)
Glicósidos Cardíacos/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Animales , Membrana Celular/metabolismo , ATPasa Intercambiadora de Hidrógeno-Potásio/biosíntesis , ATPasa Intercambiadora de Hidrógeno-Potásio/metabolismo , Insuficiencia Cardíaca/metabolismo , Insuficiencia Cardíaca/terapia , Humanos , Inmunohistoquímica , Espacio Intracelular/metabolismo , Isoenzimas/biosíntesis , Isoenzimas/metabolismo , Miocitos Cardíacos/citología , Ouabaína/metabolismo , Unión Proteica , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/genética , ATPasa Intercambiadora de Sodio-Potasio/biosíntesis , Especificidad por Sustrato
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