Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
1.
Article in English | MEDLINE | ID: mdl-38768299

ABSTRACT

Longitudinal dyssynchrony correction and strain improvement by comparable cardiac resynchronization therapy techniques is unreported. AIMS: Our purpose was to compare echocardiographic dyssynchrony correction and strain improvement by conduction system pacing (CSP) vs. biventricular pacing (BiVP) as a marker of contractility improvement during one-year follow-up. METHODS AND RESULTS: A treatment-received analysis was performed in patients included in the LEVEL-AT trial (NCT04054895), randomized to CSP or BiVP, and evaluated at baseline (ON and OFF programming) and at 6 and 12 months (n = 69, 32% women). Analysis included intraventricular (septal flash), interventricular (difference between left and right ventricular outflow times), and atrioventricular (diastolic filling time) dyssynchrony and strain parameters (septal bounce, global longitudinal strain [GLS], left bundle branch block pattern and mechanical dispersion).Baseline left ventricular ejection fraction (LVEF) was 27.5 ± 7% and left ventricular end-systolic volume (LVESV) was 138 ± 77 ml, without differences between groups. Longitudinal analysis showed LVEF and LVESV improvement (p < 0.001), without between-group differences. At 12-month follow-up, adjusted mean LVEF was 46% with CSP (95%CI 42.2%, 49.3%) vs. 43% with BiVP (95%CI 39.6%, 45.8%) (p = 0.31) and LVESV was 80 ml (95%CI 55.3 ml, 104.5 ml) vs. 100 ml (95%CI 78.7 ml, 121.6 ml), respectively (p = 0.66).Longitudinal analysis showed a significative improvement of all dyssynchrony parameters and GLS over time (p < 0.001), without differences between groups. Baseline GLS significantly correlated with LVEF and LVESV at 12-month follow-up. CONCLUSION: CSP and BiVP provided similar dyssynchrony and strain correction over time. Baseline global longitudinal strain correction predicted ventricular remodeling at 12-month follow-up.

2.
Europace ; 25(6)2023 06 02.
Article in English | MEDLINE | ID: mdl-37294671

ABSTRACT

AIMS: To define a stepwise application of left bundle branch pacing (LBBP) criteria that will simplify implantation and guarantee electrical resynchronization. Left bundle branch pacing has emerged as an alternative to biventricular pacing. However, a systematic stepwise criterion to ensure electrical resynchronization is lacking. METHODS AND RESULTS: A cohort of 24 patients from the LEVEL-AT trial (NCT04054895) who received LBBP and had electrocardiographic imaging (ECGI) at 45 days post-implant were included. The usefulness of ECG- and electrogram-based criteria to predict accurate electrical resynchronization with LBBP were analyzed. A two-step approach was developed. The gold standard used to confirm resynchronization was the change in ventricular activation pattern and shortening in left ventricular activation time, assessed by ECGI. Twenty-two (91.6%) patients showed electrical resynchronization on ECGI. All patients fulfilled pre-screwing requisites: lead in septal position in left-oblique projection and W paced morphology in V1. In the first step, presence of either right bundle branch conduction delay pattern (qR or rSR in V1) or left bundle branch capture Plus (QRS ≤120 ms) resulted in 95% sensitivity and 100% specificity to predict LBBP resynchronization, with an accuracy of 95.8%. In the second step, the presence of selective capture (100% specificity, only 41% sensitivity) or a spike-R <80 ms in non-selective capture (100% specificity, sensitivity 46%) ensured 100% accuracy to predict resynchronization with LBBP. CONCLUSION: Stepwise application of ECG and electrogram criteria may provide an accurate assessment of electrical resynchronization with LBBP (Graphical abstract).


Subject(s)
Bundle of His , Cardiac Resynchronization Therapy , Humans , Bundle-Branch Block/diagnosis , Bundle-Branch Block/therapy , Cardiac Pacing, Artificial/methods , Cardiac Resynchronization Therapy/methods , Electrocardiography/methods , Heart Conduction System , Treatment Outcome
3.
JACC Clin Electrophysiol ; 8(11): 1431-1445, 2022 11.
Article in English | MEDLINE | ID: mdl-36424012

ABSTRACT

BACKGROUND: Conduction system pacing (CSP) has emerged as an alternative to biventricular pacing (BiVP). Randomized studies comparing both therapies are scarce and do not include left bundle branch pacing. OBJECTIVES: This study aims to compare ventricular resynchronization achieved by CSP vs BiVP in patients with cardiac resynchronization therapy indication. METHODS: LEVEL-AT (Left Ventricular Activation Time Shortening with Conduction System Pacing vs Biventricular Resynchronization Therapy) was a randomized, parallel, controlled, noninferiority trial. Seventy patients with cardiac resynchronization therapy indication were randomized 1:1 to BiVP or CSP, and followed up for 6 months. Crossover was allowed when primary allocation procedure failed. Primary endpoint was the change in left ventricular activation time, measured using electrocardiographic imaging. Secondary endpoints were left ventricular reverse remodeling and the combined endpoint of heart failure hospitalization or death at 6-month follow-up. RESULTS: Thirty-five patients were allocated to each group. Eight (23%) patients crossed over from CSP to BiVP; 2 patients (6%) crossed over from BiVP to CSP. Electrocardiographic imaging could not be performed in 2 patients in each group. A similar decrease in left ventricular activation time was achieved by CSP and BiVP (-28 ± 26 ms vs -21 ± 20 ms, respectively; mean difference -6.8 ms; 95% CI: -18.3 ms to 4.6 ms; P < 0.001 for noninferiority). Both groups showed a similar change in left ventricular end-systolic volume (-37 ± 59 mL CSP vs -30 ± 41 mL BiVP; mean difference: -8 mL; 95% CI: -33 mL to 17 mL; P = 0.04 for noninferiority) and similar rates of mortality or heart failure hospitalizations (2.9% vs 11.4%, respectively) (P = 0.002 for noninferiority). CONCLUSIONS: Similar degrees of cardiac resynchronization, ventricular reverse remodeling, and clinical outcomes were attained by CSP as compared to BiVP. CSP could be a feasible alternative to BiVP. (LEVEL-AT [Left Ventricular Activation Time Shortening With Conduction System Pacing vs Biventricular Resynchronization Therapy]; NCT04054895).


Subject(s)
Cardiac Resynchronization Therapy , Heart Failure , Humans , Cardiac Resynchronization Therapy/methods , Heart Conduction System , Bundle-Branch Block , Cardiac Conduction System Disease/therapy , Ventricular Remodeling
4.
Ann Thorac Cardiovasc Surg ; 28(5): 342-348, 2022 Oct 20.
Article in English | MEDLINE | ID: mdl-35851568

ABSTRACT

PURPOSE: Our aim was to evaluate the development of new significant mitral regurgitation and long-term survival after mitral repair surgery in functional mitral regurgitation. METHODS: A retrospective observational analysis of the recurrence of functional mitral regurgitation (ischemic and nonischemic) and global mortality during follow-up of 176 patients who underwent mitral repair surgery between 1999 and 2018 in our center was conducted. RESULTS: The etiology of functional mitral regurgitation was ischemic in 55.7% of cases. After surgery, mitral regurgitation was 0-I in 92.3% of cases. We conducted a long-term clinical follow-up of a mean 42.2 months and an echocardiographic follow-up of a mean 41.8 months. We observed mitral regurgitation of at least grade II in 52 patients (36.9%). Survival at 1, 3, and 5 years was 78.8%, 66.7%, and 52.3%, respectively. Predictive factors for global mortality were age (hazard ratio = 1.038, p = 0.01) and a depressed preoperative ejection fraction. After a competing risk analysis, we found the only predictive factor for the recurrence of mitral regurgitation in our series to be age (sub-hazard ratio = 1.03, 95% confidence interval = 1.01-1.06, p = 0.016). CONCLUSION: Repair surgery for functional mitral regurgitation shows age as the only independent predictor of recurrence. Age and depressed ejection fraction were predictors of mortality.


Subject(s)
Mitral Valve Insufficiency , Humans , Mitral Valve Insufficiency/diagnostic imaging , Mitral Valve Insufficiency/surgery , Mitral Valve Insufficiency/etiology , Mitral Valve/diagnostic imaging , Mitral Valve/surgery , Retrospective Studies , Treatment Outcome , Prognosis
5.
Pacing Clin Electrophysiol ; 45(9): 1115-1123, 2022 09.
Article in English | MEDLINE | ID: mdl-35583311

ABSTRACT

BACKGROUND: It is unknown whether His-Purkinje conduction system pacing (HPCSP), as either His bundle or left bundle branch pacing, could be an alternative to cardiac resynchronization therapy (BiVCRT) for patients with left ventricular dysfunction needing ventricular pacing due to atrioventricular block. The aim of the study is to compare the echocardiographic response and clinical improvement between HPCSP and BiVCRT. METHODS: Consecutive patients who successfully received HPCSP were compared with a historical cohort of BiVCRT patients. Patients were 1:1 matched by age, LVEF, atrial fibrillation, renal function and cardiomyopathy type. Responders were defined as patients who survived, did not require heart transplantation and increased LVEF ≥5 points at 6-month follow-up. RESULTS: HPCSP was successfully achieved in 92.5% (25/27) of patients. During follow-up, 8% (2/25) of HPCSP patients died and 4% (1/25) received a heart transplant, whereas 4% (1/25) of those in the BiVCRT cohort died. LVEF improvement was 10% ± 8% HPCSP versus 7% ± 5% BiVCRT (p = .24), and the percentage of responders was 76% (19/25) HPCSP versus 64% (16/25) BiVCRT (p = .33). Among survivors, the percentage of patients who improved from baseline II-IV mitral regurgitation (MR) to 0-I MR was 9/11 (82%) versus 2/8 (25%) (p = .02). Compared to those with BiVCRT, patients with HPCSP achieved better NYHA improvement: 1 point versus 0.5 (OR 0.34; p = .02). CONCLUSION: HPCSP in patients with LVEF ≤45% and atrioventricular block improved the LVEF and induced a response similar to that of BiVCRT. HPCSP significantly improved MR and NYHA functional class. HPCSP may be an alternative to BiVCRT in these patients. (Figure 1. Central Illustration). [Figure: see text].


Subject(s)
Atrioventricular Block , Cardiac Resynchronization Therapy , Heart Failure , Ventricular Dysfunction , Bundle of His , Cardiac Conduction System Disease , Cardiac Pacing, Artificial/adverse effects , Cardiac Resynchronization Therapy/adverse effects , Heart Failure/therapy , Humans , Stroke Volume , Treatment Outcome , Ventricular Dysfunction/etiology , Ventricular Dysfunction/therapy , Ventricular Function, Left
6.
Pacing Clin Electrophysiol ; 45(3): 374-383, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35015308

ABSTRACT

BACKGROUND: His-Purkinje conduction system pacing (HPCSP) has been proposed as an alternative to Cardiac Resynchronization Therapy (CRT); however, predictors of echocardiographic response have not been described in this population. Septal flash (SF), a fast contraction and relaxation of the septum, is a marker of intraventricular dyssynchrony. METHODS: The study aimed to analyze whether HPCSP corrects SF in patients with CRT indication, and if correction of SF predicts echocardiographic response. This retrospective analysis of prospectively collected data included 30 patients. Left ventricular ejection fraction (LVEF) was measured with echocardiography at baseline and at 6-month follow-up. Echocardiographic response was defined as increase in five points in LVEF. RESULTS: HPCSP shortened QRS duration by 48 ± 21 ms and SF was significantly decreased (baseline 3.6 ± 2.2 mm vs. HPCSP 1.5 ± 1.5 mm p < .0001). At 6-month follow-up, mean LVEF improvement was 8.6% ± 8.7% and 64% of patients were responders. There was a significant correlation between SF correction and increased LVEF (r = .61, p = .004). A correction of ≥1.5 mm (baseline SF - paced SF) had a sensitivity of 81% and 80% specificity to predict echocardiographic response (area under the curve 0.856, p = .019). CONCLUSION: HPCSP improves intraventricular dyssynchrony and results in 64% echocardiographic responders at 6-month follow-up. Dyssynchrony improvement with SF correction may predict echocardiographic response at 6-month follow-up.


Subject(s)
Cardiac Resynchronization Therapy , Heart Failure , Ventricular Dysfunction, Left , Cardiac Pacing, Artificial , Cardiac Resynchronization Therapy/methods , Echocardiography , Heart Failure/therapy , Heart Ventricles , Humans , Retrospective Studies , Stroke Volume/physiology , Treatment Outcome , Ventricular Dysfunction, Left/prevention & control , Ventricular Function, Left
7.
JACC Clin Electrophysiol ; 7(11): 1400-1409, 2021 11.
Article in English | MEDLINE | ID: mdl-34217660

ABSTRACT

OBJECTIVES: This study hypothesized that the shorter intrinsic PR interval observed in women allows a greater degree of fusion with intrinsic conduction, achieving a shorter QRS interval duration and, thus, a better response. BACKGROUND: Women benefit more from cardiac resynchronization therapy (CRT) than men. However, the reason for this difference remains elusive. METHODS: A cohort of 180 patients included in the BEST (Fusion based optimization in resynchronization therapy [ECG Optimization of CRT: Evaluation of Mid-Term Response]; NCT01439529) study were retrospectively analyzed. Patients were initially randomized to either nonoptimized CRT (NON-OPT group; n = 89) or electrocardiographically optimized CRT based on the fusion-optimized intervals (FOI) method (FOI group; n = 91). Echocardiographic response was defined as a >15% decrease in left ventricular end-systolic volume at the 12-month follow-up. RESULTS: The basal PR interval was shorter in women as compared to men. In the NON-OPT group, CRT resulted in a shorter paced QRS interval in women than in men (134 ± 21 ms vs. 151 ± 21 ms, respectively; p = 0.003, 95% confidence interval [CI]: -27 to -5.6) and better response in women than in men: 70.4% vs. 46.4%, respectively (odds ratio: 0.37; p = 0.04; 95% CI: 0.14 to 0.97). There were no differences in paced QRS interval duration (126 ± 13 ms vs. 129 ± 17 ms; p = 0.47) or response between women and men in the FOI group (68% vs. 70.5%; odds ratio: 1.12; p = 0.82; 95% CI: 0.41 to 3.07). FOI extended the atrioventricular interval to obtain the best fusion; the atrioventricular intervals tended to require greater extension in men than in women (22 ± 33 ms vs. 8 ± 28 ms, respectively; p = 0.07). CONCLUSIONS: Women had a shorter PR interval, which was associated with a shorter QRS interval and better response to CRT. The difference in QRS interval duration and response between men and women did not persist when CRT was optimized using fusion with intrinsic conduction (FOI programming).


Subject(s)
Cardiac Resynchronization Therapy , Heart Failure , Cardiac Resynchronization Therapy Devices , Female , Heart Failure/therapy , Heart Rate , Humans , Male , Retrospective Studies
8.
Pacing Clin Electrophysiol ; 44(3): 519-527, 2021 03.
Article in English | MEDLINE | ID: mdl-33538337

ABSTRACT

BACKGROUND: Multipoint pacing (MPP) in cardiac resynchronization therapy (CRT) activates the left ventricle from two locations, thereby shortening the QRS duration and enabling better resynchronization; however, compared with conventional CRT, MPP reduces battery longevity. On the other hand, electrocardiogram-based optimization using the fusion-optimized intervals (FOI) method achieves more significant reverse remodeling than nominal CRT programming. Our study aimed to determine whether MPP could attain better resynchronization than single-point pacing (SPP) optimized by FOI. METHODS: This prospective study included 32 consecutive patients who successfully received CRT devices with MPP capabilities. After implantation, the QRS duration was measured during intrinsic rhythm and with three pacing configurations: MPP, SPP-FOI, and MPP-FOI. In 14 patients, biventricular activation times (by electrocardiographic imaging, ECGI) were obtained during intrinsic rhythm and for each pacing configuration to validate the findings. Device battery longevity was estimated at the 45-day follow-up. RESULTS: The SPP-FOI method achieved greater QRS shortening than MPP (-56 ± 16 vs. -42 ± 17 ms, p < .001). Adding MPP to the best FOI programming did not result in further shortening (MPP-FOI: -58 ± 14 ms, p = .69). Although biventricular activation times did not differ significantly among the three pacing configurations, only the two FOI configurations achieved significant shortening compared with intrinsic rhythm. The estimated battery longevity was longer with SPP than with MPP (8.1 ± 2.3 vs. 6.3 ± 2.0 years, p = .03). CONCLUSIONS: SPP optimized by FOI resulted in better resynchronization and longer battery duration than MPP.


Subject(s)
Cardiac Resynchronization Therapy/methods , Ventricular Dysfunction, Left/therapy , Aged , Echocardiography , Electric Power Supplies , Electrocardiography , Female , Humans , Male , Middle Aged , Prospective Studies , Ventricular Dysfunction, Left/physiopathology
9.
Rev. esp. cardiol. (Ed. impr.) ; 73(8): 643-651, ago. 2020. tab, graf
Article in Spanish | IBECS | ID: ibc-198250

ABSTRACT

INTRODUCCIÓN Y OBJETIVOS: La reparación de la válvula mitral transcatéter (RVMT) con el sistema MitraClip es un tratamiento para los pacientes con insuficiencia mitral (IM) grave de alto riesgo quirúrgico. El objetivo principal fue analizar los resultados del RVMT en pacientes con IM grave, según la etiología. MÉTODOS: Estudio observacional, prospectivo y multicéntrico con inclusión de pacientes consecutivos. El objetivo primario fue el combinado de mortalidad por todas las causas y reingresos hospitalarios por insuficiencia cardiaca al año. Se compararon las características clínicas y del procedimiento y los eventos para cada grupo de IM. Se realizó un análisis multivariable para determinar las variables asociadas con el objetivo primario. RESULTADOS: Se incluyó a 558 pacientes; 364 (65,2%) tenían etiología funcional; 111 (19,9%), degenerativa, y 83 (14,9%), mixta. La media de edad fue 72,8±11,1 años y eran varones el 70,3%. Respecto al objetivo primario, hubo 95 (17%) eventos en toda la serie. No hubo diferencias significativas entre los 3 grupos en el número de eventos del objetivo primario: 11 (11,3%) en la IM degenerativa, 71 (21,3%) en la funcional y 13 (18,1%) en la mixta (p = 0,101). Los predictores independientes fueron la clase funcional (p = 0,029), la revascularización quirúrgica previa (p = 0,031), el EuroSCORE II (p = 0,003), la diabetes mellitus (p = 0,037) y la fracción de eyección del ventrículo izquierdo (p = 0,015). CONCLUSIONES: Este trabajo confirma con datos de la práctica clínica la seguridad y la eficacia de la RVMT independientemente de la etiología de la IM y se documentan los principales factores asociados con el pronóstico durante el primer año de seguimiento


INTRODUCTION AND OBJECTIVES: Transcatheter mitral valve repair (TMVR) with MitraClip is a therapeutic option for high surgical risk patients with severe mitral regurgitation (MR). The main objective of this study was to analyze differences in outcomes in patients with severe MR according to the cause of MR. METHODS: Observational, multicenter, and prospective study with consecutive patient inclusion. The primary endpoint was the combination of all-cause mortality and new readmissions due to heart failure after 1 year. We compared clinical and procedural characteristics and the event rate for each MR group. We performed a multivariate analysis to identify predictive variables for the primary endpoint. RESULTS: A total of 558 patients were included: 364 (65.2%) with functional etiology, 111 (19.9%) degenerative and 83 (14.9%) mixed. The mean age was 72.8±11.1 years and 70.3% of the sample were men. There were 95 (17%) events in the overall sample. No significant differences were found in the 3 groups in the number of primary outcome events: 11 (11.3%) in degenerative MR, 71 (21.3%) in functional MR, and 13 (18.1%) in mixed MR (P=.101). Independent predictors were functional class (P=.029), previous surgical revascularization (P=.031), EuroSCORE II (P=.003), diabetes mellitus (P=.037), and left ventricular ejection fraction (P=.015). CONCLUSIONS: This study confirms the safety and efficacy of TMVR with MitraClip irrespective of MR etiology in real-life data and shows the main factors related to prognosis during the first year of follow up


Subject(s)
Humans , Male , Female , Middle Aged , Aged , Aged, 80 and over , Mitral Valve Insufficiency/surgery , Heart Valve Prosthesis Implantation/methods , Heart-Assist Devices , Ventricular Dysfunction, Left/classification , Treatment Outcome , Patient Safety , Severity of Illness Index , Prospective Studies , Cardiac Catheterization/methods , Spain/epidemiology
10.
JACC Case Rep ; 2(14): 2225-2229, 2020 Nov 18.
Article in English | MEDLINE | ID: mdl-34317145

ABSTRACT

His bundle pacing was developed while seeking a physiological alternative to biventricular cardiac resynchronization therapy. However, His bundle pacing may not be adequate in all patients. In this scenario, left bundle branch pacing has arisen as a new cardiac resynchronization therapy modality to correct left bundle branch block and restore ventricular synchrony. (Level of Difficulty: Intermediate.).

11.
Rev Esp Cardiol (Engl Ed) ; 73(8): 643-651, 2020 Aug.
Article in English, Spanish | MEDLINE | ID: mdl-31732437

ABSTRACT

INTRODUCTION AND OBJECTIVES: Transcatheter mitral valve repair (TMVR) with MitraClip is a therapeutic option for high surgical risk patients with severe mitral regurgitation (MR). The main objective of this study was to analyze differences in outcomes in patients with severe MR according to the cause of MR. METHODS: Observational, multicenter, and prospective study with consecutive patient inclusion. The primary endpoint was the combination of all-cause mortality and new readmissions due to heart failure after 1 year. We compared clinical and procedural characteristics and the event rate for each MR group. We performed a multivariate analysis to identify predictive variables for the primary endpoint. RESULTS: A total of 558 patients were included: 364 (65.2%) with functional etiology, 111 (19.9%) degenerative and 83 (14.9%) mixed. The mean age was 72.8±11.1 years and 70.3% of the sample were men. There were 95 (17%) events in the overall sample. No significant differences were found in the 3 groups in the number of primary outcome events: 11 (11.3%) in degenerative MR, 71 (21.3%) in functional MR, and 13 (18.1%) in mixed MR (P=.101). Independent predictors were functional class (P=.029), previous surgical revascularization (P=.031), EuroSCORE II (P=.003), diabetes mellitus (P=.037), and left ventricular ejection fraction (P=.015). CONCLUSIONS: This study confirms the safety and efficacy of TMVR with MitraClip irrespective of MR etiology in real-life data and shows the main factors related to prognosis during the first year of follow up.


Subject(s)
Heart Valve Prosthesis Implantation , Mitral Valve Insufficiency , Aged , Aged, 80 and over , Cardiac Catheterization , Female , Humans , Male , Middle Aged , Mitral Valve/diagnostic imaging , Mitral Valve/surgery , Mitral Valve Insufficiency/epidemiology , Mitral Valve Insufficiency/surgery , Prospective Studies , Registries , Stroke Volume , Treatment Outcome , Ventricular Function, Left
12.
Biopharm Drug Dispos ; 24(4): 165-71, 2003 May.
Article in English | MEDLINE | ID: mdl-12698500

ABSTRACT

The steady-state pharmacokinetics of an ultralong sustained release formulation of theophylline (Unilong) twice daily (bid) in elderly hospitalized patients suffering from chronic obstructive pulmonary disease (COPD) have been studied in order to establish guidelines for monitoring. The study was carried out in 37 patients (33 men), aged 60-87 years. Samples were collected from 0 to 12 h after the morning dose on day 9 of treatment with 250 mg bid (n=25) or 375 mg bid (n=12). Considerable variability in apparent clearance (range 0.33-1.49 ml/min per kg of ideal body weight), Css(min)/D (range 0.28-1.86), Css(max)/D (range 0.65-2.33) and (Css(max)-Css(min))/Css(avg) (range 0.18-0.80) was observed. There was no significant correlation between the patient's age and apparent clearance within this elderly population. The concentration-to-dose ratio and the relationship between the steady-state plasma concentration at different times during the dosage interval and Css(avg) are described. It is concluded that the interpatient variability in peak-trough fluctuation of this formulation was higher than that described in healthy volunteers by other investigators, and that the apparent clearance did not decrease with age within this elderly population with COPD. The importance of theophylline monitoring is emphasized and rules to estimate Css(avg) and Css(5h) from Css(0h) when only a single sample obtained before the morning dose is available are given.


Subject(s)
Pulmonary Disease, Chronic Obstructive/drug therapy , Theophylline/administration & dosage , Theophylline/pharmacokinetics , Adult , Age Factors , Aged , Delayed-Action Preparations , Dose-Response Relationship, Drug , Female , Humans , Inpatients , Male , Middle Aged , Pulmonary Disease, Chronic Obstructive/metabolism , Theophylline/blood
SELECTION OF CITATIONS
SEARCH DETAIL
...