A detection system of exercise electrocardiogram / Um sistema de detecção de eletrocardiograma de exercício / Un sistema de detección de electrocardiograma de ejercicio

ABSTRACT Introduction: A new exercise electrocardiogram (ECG) detection system was investigated in this study to diagnose and analyze cardiopulmonary function and related diseases in a comprehensive and timely manner and improve the accuracy of diagnosis. Besides, its reliability and clinical applicability were judged. Objective: A new type of exercise ECG detection system was constructed by adding parameters such as respiratory mechanics, carbon dioxide, and oxygen concentration monitoring based on the traditional ECG detection system. Methods: The new system constructed in this study carried out the ECG signal detection, ECG acquisition module, blood pressure and respiratory mechanics detection and conducted a standard conformance test. Results: The heart rate accuracy detected by the exercise ECG system was greatly higher than that of the doctor's manual detection (P < 0.05). The accuracy of the new exercise ECG detection system increased obviously in contrast to that of the manual detection result (P < 0.05). The key technical index input noise and input impedance test results (24.5 μV and 12.4 MΩ) of the exercise ECG detection system conformed to the standard (< 30 μV and > 2.5 MΩ). The common-mode rejection and sampling rate test results (103.5 dB and 515 Hz) of key technical indicators in the exercise ECG detection system were all in line with the standards (≥89 dB and ≥500 Hz). Conclusion: The complete exercise ECG detection system was constructed through the ECG acquisition module, blood pressure detection, and respiratory mechanics detection module. In addition, this system could be applied to detect ECG monitoring indicators with high accuracy and reliability, which could also be extensively adopted in clinical diagnosis. Level of evidence II; Therapeutic studies - investigation of treatment results.

RESUMO Introdução: Um novo sistema de detecção de eletrocardiograma de exercício (ECG) foi investigado neste estudo para diagnosticar e analisar a função cardiopulmonar e doenças relacionadas de maneira abrangente e oportuna e melhorar a precisão do diagnóstico. Além disso, sua confiabilidade e aplicabilidade clínica foram julgadas. Objetivo: Um novo tipo de sistema de detecção de ECG de esforço foi construído adicionando parâmetros como mecânica respiratória, dióxido de carbono e monitoramento da concentração de oxigênio com base no sistema de detecção de ECG tradicional. Métodos: O novo sistema construído neste estudo realizou a detecção do sinal de ECG, módulo de aquisição de ECG e detecção de pressão arterial e mecânica respiratória, e conduziu um teste de conformidade padrão. Resultados: A precisão da frequência cardíaca detectada pelo sistema de ECG de esforço foi muito maior do que a detecção manual do médico (P <0,05). A precisão do novo sistema de detecção de ECG de esforço aumentou obviamente em contraste com o resultado da detecção manual (P <0,05). O ruído de entrada do índice técnico principal e os resultados do teste de impedância de entrada (24,5 μV e 12,4 MΩ) do sistema de detecção de ECG de esforço estão em conformidade com o padrão (<30 μV e> 2,5 MΩ). A rejeição do modo comum e os resultados do teste de taxa de amostragem (103,5 dB e 515 Hz) dos indicadores técnicos principais no sistema de detecção de ECG de esforço estavam todos alinhados com os padrões (≥89 dB e ≥500 Hz). Conclusão: O sistema completo de detecção de ECG de esforço foi construído através da combinação de módulo de aquisição de ECG, detecção de pressão arterial e módulo de detecção de mecânica respiratória. Além disso, esse sistema poderia ser aplicado à detecção de indicadores de monitoramento de ECG com alta precisão e confiabilidade, o que poderia ser amplamente adotado no diagnóstico clínico. Nível de evidência II; Estudos terapêuticos- investigação dos resultados do tratamento.

RESUMEN Introducción: En este estudio se investigó un nuevo sistema de detección de electrocardiograma de esfuerzo (ECG) para diagnosticar y analizar la función cardiopulmonar y enfermedades relacionadas de manera integral y oportuna, y mejorar la precisión del diagnóstico. Además, se evaluó su confiabilidad y aplicabilidad clínica. Objetivo: Se construyó un nuevo tipo de sistema de detección de ECG de ejercicio agregando parámetros como la mecánica respiratoria, el dióxido de carbono y el monitoreo de la concentración de oxígeno sobre la base del sistema de detección de ECG tradicional. Métodos: El nuevo sistema construido en este estudio llevó a cabo la detección de la señal de ECG, el módulo de adquisición de ECG y la detección de la presión arterial y la mecánica respiratoria, y realizó una prueba de conformidad estándar. Resultados: la precisión de la frecuencia cardíaca detectada por el sistema de ECG de ejercicio fue mucho mayor que la de la detección manual del médico (P <0,05). La precisión del nuevo sistema de detección de ECG de esfuerzo aumentó obviamente en contraste con el resultado de la detección manual (P <0.05). Los resultados de la prueba de impedancia de entrada y ruido de entrada de índice técnico clave (24,5 μV y 12,4 MΩ) del sistema de detección de ECG de esfuerzo cumplieron con el estándar (<30 μV y> 2,5 MΩ). Los resultados de la prueba de frecuencia de muestreo y rechazo en modo común (103,5 dB y 515 Hz) de los indicadores técnicos clave en el sistema de detección de ECG de esfuerzo estaban en línea con los estándares (≥89 dB y ≥500 Hz). Conclusión: El sistema completo de detección de ECG de ejercicio se construyó mediante la combinación del módulo de adquisición de ECG, la detección de la presión arterial y el módulo de detección de la mecánica respiratoria. Además, este sistema podría aplicarse a la detección de indicadores de monitoreo de ECG con alta precisión y confiabilidad, que también podría adoptarse ampliamente en el diagnóstico clínico. Nivel de evidencia II; Estudios terapéuticos- investigación de los resultados del tratamiento.

Arduino control of a pulsatile flow rig.

This note describes the design and testing of a programmable pulsatile flow pump using an Arduino micro-controller. The goal of this work is to build a compact and affordable system that can relatively easily be programmed to generate physiological waveforms. The system described here was designed to be used in an in-vitro set-up for vascular access hemodynamics research, and hence incorporates a gear pump that delivers a mean flow of 900 ml/min in a test flow loop, and a peak flow of 1106 ml/min. After a number of simple identification experiments to assess the dynamic behaviour of the system, a feed-forward control routine was implemented. The resulting system was shown to be able to produce the targeted representative waveform with less than 3.6% error. Finally, we outline how to further increase the accuracy of the system, and how to adapt it to specific user needs.

Synchrotron radiation imaging for advancing our understanding of cardiovascular function.

Synchrotron radiation (SR) is increasingly being used for micro-level and nano-level functional imaging in in vivo animal experiments. This review focuses on the methodology that enables repeated and regional assessment of vessel internal diameter and flow in the resistance vessels of different organ systems. In particular, SR absorption microangiography approaches offer unique opportunities for real-time in vivo vascular imaging in small animals, even during dynamic motion of the heart and lungs. We also describe recent progress in the translation of multiple phase-contrast imaging techniques from ex vivo to in vivo small-animal studies. Furthermore, we also review the utility of SR for multiple pinpoint (dimensions 0.2×0.2 mm) assessments of myocardial function at the cross-bridge level in different regions of the heart using small-angle X-ray scattering, resulting from increases in SR flux at modern facilities. Finally, we present cases for the use of complementary SR approaches to study cardiovascular function, particularly the pathological changes associated with disease using small-animal models.

Principles, current status and clinical implications of ischaemic heart disease assessment by cardiac magnetic resonance imaging.

Cardiac magnetic resonance imaging (CMR) has matured into a robust, accurate and highly reproducible imaging modality for the assessment of cardiac function and ischaemic heart disease. The unique physical properties of CMR permit depiction of pathology-specific tissue contrast based on differences in tissue composition, such as myocardial oedema, necrosis and fibrosis. This can be imaged at high spatial resolution allowing characterisation of the acuity of an ischaemic event, the presence and extent of myocardial ischaemia, necrosis and viability. Prognostically important information obtained from CMR evaluation of ischaemic heart disease, such as left ventricular ejection fraction, infarct size and transmurality, infarct location and the presence of intraventricular mechanical dyssynchrony may be used to guide coronary revascularisation, device and medical therapies.

Flow-regulated extracorporeal arteriovenous tubing loop for cardiac output measurements by ultrasound velocity dilution: validation in post-cardiac surgery intensive care unit patients.

Assessment of cardiac output (CO) is crucial in the management of the critically ill, especially in post cardiac surgery intensive care unit (ICU) patients. In this study, we validated CO measured by the novel ultrasound dilution (COUD) with those measured by pulmonary artery (PA) thermodilution (COTD) in 26 adult post cardiac surgery patients. For COUD, blood was circulated through an extracorporeal arteriovenous (AV) loop from the radial artery catheter to the introducer of PA catheter for 5-8 minutes. Three to four injections of 25 ml body temperature isotonic saline were performed into the venous limb of the AV loop. For COTD, five injections of 10 ml ice cold saline were performed. A total of 77 COUD and COTD measurement sets were compared. Cardiac output measured by thermodilution ranged from 3.28 to 9.4 L/min, whereas COUD ranged from 2.85 to 10.1 L/min. The correlation between the methods was found to be r = 0.91, COUD = 0.93(COTD) + 0.42 L/min. Bias and precision (mean difference ± 2SDs) was -0.004 ± 1.34 L/min between the two methods. The percentage error (2SD/mean) was 22.2%, which is below the clinically acceptable limit (<30%). Cardiac output measured by ultrasound dilution and thermodilution methods agreed well in post cardiac surgery ICU patients and hence can be interchangeably used.

Comparison between Flotrac-Vigileo and Bioreactance, a totally noninvasive method for cardiac output monitoring.

INTRODUCTION: This study was designed to compare the clinical acceptability of two cardiac output (CO) monitoring systems: a pulse wave contour-based system (FloTrac-Vigileo) and a bioreactance-based system (NICOM), using continuous thermodilution (PAC-CCO) as a reference method. METHODS: Consecutive patients, requiring PAC-CCO monitoring following cardiac surgery, were also monitored by the two other devices. CO values obtained simultaneously by the three systems were recorded continuously on a minute-by-minute basis. RESULTS: Continuous recording was performed on 29 patients, providing 12,099 simultaneous measurements for each device (417 +/- 107 per patient). In stable conditions, correlations of NICOM and Vigileo with PAC-CCO were 0.77 and 0.69, respectively. The bias was -0.01 +/- 0.84 for NICOM and -0.01 +/- 0.81 for Vigileo (NS). NICOM relative error was less than 30% in 94% of the patients and less than 20% in 79% vs. 91% and 79% for the Vigileo, respectively (NS). The variability of measurements around the trend line (precision) was not different between the three methods: 8 +/- 3%, 8 +/- 4% and 8 +/- 3% for PAC-CCO, NICOM and Vigileo, respectively. CO changes were 7.2 minutes faster with Vigileo and 6.9 minutes faster with NICOM (P < 0.05 both systems vs. PAC-CCO, NS). Amplitude of changes was not significantly different than thermodilution. Finally, the sensitivity and specificity for predicting significant CO changes were 0.91 and 0.95 respectively for the NICOM and 0.86 and 0.92 respectively for the Vigileo. CONCLUSION: This study showed that the NICOM and Vigileo devices have similar monitoring capabilities in post-operative cardiac surgery patients.

[Comparison of three kinds of less invasive cardiac output measuring systems in aged patients].

BACKGROUND: Recently, the number of operations for aged patients have been increasing. They usually have various preoperative complications especially cardiovascular systems, and cardiac output measuring under general anesthesia is useful for their operative managements. The aim of this study was to compare the accuracy of three kinds of less invasive equipments for cardiac output measurements, i.e. the impedance cardiography (ICG), the partial CO2 rebreathing (NICO), and the arterial pressure-based cardiac output (APCO). METHODS: Subjects are 40 patients over 65 years of age scheduled for elective lower abdominal or surface surgery. During anesthesia, three kinds of cardiac output measuring systems obtained cardiac output simultaneously every five minutes. RESULTS: Both bias and percentage error between APCO and NICO were the smallest. There were statistically significant correlations between ICG and NICO, NICO and APCO, and APCO and ICG. Accuracy of the three kinds of cardiac output measuring systems was confirmed in this study. Although when arterial pressure was above 100 mmHg cardiac output values were reliable, values were not reliable below 100 mmHg. The four factors i. e. age, blood pressure level, history of hypertension and body structure effected cardiac output measurements. There was no statistic relationship between arterial pressure and cardiac output in all measurements. CONCLUSIONS: Three kinds of less invasive cardiac output measurement systems have enough functions to use during surgery for aged patients.

Cardiac output derived from arterial pressure waveform analysis in patients undergoing cardiac surgery: validity of a second generation device.

BACKGROUND: The performance of a recently introduced, arterial waveform-based device for measuring cardiac output (CO) without the need of invasive calibration (FloTrac/Vigileo) has been controversial. We designed the present study to assess the validity of an improved version of this monitoring technique compared with intermittent thermodilution CO measurement using a pulmonary artery catheter in patients undergoing cardiac surgery. METHODS: Forty ASA III patients scheduled for elective coronary artery bypass grafting with cardiopulmonary bypass (CPB) were studied. Simultaneous CO measurements by bolus thermodilution and the FloTrac/Vigileo device were obtained after induction of anesthesia (T1), before CPB (T2), after CPB (T3), after sternal closure (T4), on arrival in the intensive care unit (T5), 4 h (T6), 8 h (T7), and 24 h after surgery (T8). CO was indexed to the body surface area (cardiac index, CI). A percentage error of 30% or less was established as the criterion for method interchangeability. RESULTS: Two hundred and eighty-two data pairs were analyzed. Thermodilution CI ranged from 1.2 to 4.1 L x min(-1) x m(-2) (mean 2.5 +/- 0.54 L x min(-1) x m(-2)). Bias and precision (1.96 sd of the bias) were 0.19 L x min(-1) x m(-2) and +/- 0.60 L x min(-1) x m(-2), resulting in an overall percentage error of 24.6%. Subgroup analysis revealed a percentage error of 28.3% for data pairs obtained intraoperatively (T1-4) and 20.7% in intensive care unit (T5-8). CONCLUSION: CI values obtained by the improved, second generation semiinvasive arterial waveform device showed good intraoperative and postoperative agreement with intermittent pulmonary artery thermodilution CI measurements in patients undergoing coronary artery bypass graft surgery.

A modified cardiac stabilizer used for recording electrograms.

Originally, tissue stabilizer has been developed by Medtronic, Inc. It is used to prevent a certain part of myocardium from moving. For example, such an approach is utilized during Coronary Artery Bypass Grafting (CABG). Moreover, medical procedures during such operations involve blood arrest, thus, potentially may involve ischemia of myocardium. A construction of the modified tissue stabilizer used during surgery on a beating heart is presented in the paper. We have developed a stabilizer that aside preventing part of myocardium from moving enables recording of epicardial electrograms. Four electrograms are recorded simultaneously together with one lead of standard ECG as a reference signal. Time relations between electrograms, recorded at four different points surrounding potentially ischemic area, are strongly modified by processes triggered by myocardium ischemia. Aside a construction of the stabilizer the associated measurement system is also presented. Measurement properties of the developed stabilizer and measurement system have been examined during tank studies. Finally, the waveforms obtained during in vivo study are also presented.

Validation of a new arterial pulse contour-based cardiac output device.

OBJECTIVE: To evaluate the accuracy and precision of an arterial pulse contour-based continuous cardiac output device (Vigileo). Vigileo cardiac output (VigileoCO) was compared with intermittent transpulmonary thermodilution cardiac output (TPCO) and an established arterial pulse contour-based cardiac output (PCCO). DESIGN: Prospective clinical study. SETTING: University hospital. PATIENTS: Twenty-two patients undergoing coronary artery bypass graft surgery. INTERVENTIONS: Defined volume load during surgery and in the postoperative period. MEASUREMENTS AND MAIN RESULTS: We obtained 184 pairs of VigileoCO and TPCO, 140 pairs of VigileoCO and PCCO, and 140 pairs of PCCO and TPCO. Measurements were performed after induction of anesthesia (T1), after sternotomy (T2), immediately after (T3) and 20 mins after volume challenge with 10 mL.kg hydroxyethyl starch 6% (T4), 15 mins after coronary pulmonary bypass (T5), after retransfusion of autologous blood (T6), after arrival at the intensive care unit (T7), and immediately after (T8) and 20 mins after (T9) a second volume load with 10 mL.kg hydroxyethyl starch 6%. TPCO was used to calibrate PCCO. For pooled data, including uncalibrated PCCO data immediately after weaning from coronary pulmonary bypass (T5), the correlation coefficient of TPCO vs. VigileoCO, PCCO vs. VigileoCO, and TPCO vs. PCCO was 0.75, 0.60, and 0.75 respectively. Bland-Altman analysis showed a bias of 0.00, -0.01, and 0.02 L.min, the precision (=sd) was 0.87, 1.08, and 0.93 L.min, and the mean error was 33%, 40%, and 35%. When we compared calibrated PCCO values (T2-T4, T6, T7-9), the correlation coefficients of PCCO-VigileoCO and TPCO-PCCO were 0.72 and 0.85, bias was -0.16 and 0.19 L.min, and mean error was 33% and 27%, respectively. Best correlations and the least differences between TPCO and VigileoCO were observed in postbypass closed-chest conditions and in the intensive care unit. CONCLUSIONS: Our results showed that VigileoCO enables clinically acceptable assessment of cardiac output in postbypass closed-chest conditions and during stable conditions in the intensive care unit.

Cardiac torsion and electromagnetic fields: the cardiac bioinformation hypothesis.

Although in physiology the heart is often referred to as a simple piston pump, there are in fact two additional features that are integral to cardiac physiology and function. First, the heart as it contracts in systole, also rotates and produces torsion due to the structure of the myocardium. Second, the heart produces a significant electromagnetic field with each contraction due to the coordinated depolarization of myocytes producing a current flow. Unlike the electrocardiogram, the magnetic field is not limited to volume conduction and extends outside the body. The therapeutic potential for interaction of this cardioelectromagnetic field both within and outside the body is largely unexplored. It is our hypothesis that the heart functions as a generator of bioinformation that is central to normative functioning of body. The source of this bioinformation is based on: (1) vortex blood flow in the left ventricle; (2) a cardiac electromagnetic field and both; (3) heart sounds; and (4) pulse pressure which produce frequency and amplitude information. Thus, there is a multidimensional role for the heart in physiology and biopsychosocial dynamics. Recognition of these cardiac properties may result in significant implications for new therapies for cardiovascular disease based on increasing cardiac energy efficiency (coherence) and bioinformation from the cardioelectromagnetic field. Research studies to test this hypothesis are suggested.

Longitudinal myocardial function assessed by tissue velocity, strain, and strain rate tissue Doppler echocardiography in patients with AL (primary) cardiac amyloidosis.

BACKGROUND: AL amyloidosis with heart failure is associated with decreased longitudinal myocardial contraction measured by pulsed tissue Doppler imaging. We sought to clarify whether new modalities of myocardial strain Doppler (change in length per unit length) or strain rate (the temporal derivative of strain) were more sensitive than tissue Doppler and could detect early regional myocardial dysfunction before the onset of congestive heart failure (CHF) in patients with AL (primary) amyloidosis. METHODS AND RESULTS: Ninety-seven biopsy-proven patients with AL amyloidosis were divided into 3 groups. Group 1 patients had no cardiac involvement (n=36), group 2 had heart involvement but no CHF (n=32), and group 3 had heart involvement and CHF (n=29). All patients underwent tissue velocity (TV) imaging, strain, and strain rate imaging (SR) at the basal, mid, and apical ventricle in 2 apical views. With the use of TV, differences in systolic function were only apparent between group 3 (basal mean value, 3.0+/-1.1 cm/s) and groups 1 and 2 (5.0+/-1.3 and 4.6+/-1.2 cm/s, respectively). In contrast, basal peak systolic SR (l/s) showed significant differences among all 3 groups (-2.0+/-0.4, -1.55+/-0.6, and -0.76+/-0.3 for groups 1 to 3, respectively. P<0.01). Basal strain also demonstrated statistically significant differences among the groups (-19+/-4%, -15+/-4.5%, and -8.0+/-5%; P<0.01). CONCLUSIONS: Cardiac amyloidosis is characterized by an early impairment in systolic function at a time when fractional shortening remains normal. This abnormality precedes the onset of CHF and can be detected by strain and SR but is not apparent by TV imaging.

[Semi-invasive cardiac output measurement using a combined transesophageal ultrasound device. Early experiences]. / Semiinvasive Herzzeitvolumenmessung mittels kombiniertem ösophagealen Ultraschallkopf. Erste Erfahrungen.

OBJECTIVE: Measurement of cardiac output (CO) with pulmonary artery catheter (PAC) is currently item of many discussions. We investigated the reliability of results using the noninvasive measurement of aortic blood flow (ABF) (combined Doppler- and M-Mode transesophageal ultrasound, Dynemo 3000, Sometec Inc, Paris, France). METHODS: In 75 patients during cardiac or major abdominal surgery we performed 313 simultaneous measurements of CO and ABF. RESULTS: Placement of ultrasound probe into correct position took less than 2 min. Quality and stability of ultrasound signals were good. The coefficient of correlation between ABF and CO was found to be 0.89 with CO = 0.97 x ABF + 1.1, Bland-Altman-Test positive. CONCLUSION: Results of ABF detected by combined Doppler- and M-Mode-Echography are comparable with results of CO obtained by PAC. Therefore we are convinced that this noninvasive method will find its place in clinical situations of compromised CO.

Vascular abnormalities associated with long-term cigarette smoking identified by arterial waveform analysis.

PURPOSE: Consistent changes in the arterial pulse contour are found with aging and disease states that impair the compliance characteristics of blood vessels that buffer pulsatile phenomena in the arterial tree. We assessed whether vascular adaptation in structure or tone of blood vessels associated with long-term cigarette smoking would influence steady state or pulsatile hemodynamics at a preclinical stage. PATIENTS AND METHODS: We analyzed intraarterial brachial artery waveforms in 35 healthy long-term cigarette smokers and 32 nonsmoking control subjects matched for age and gender. The diastolic pressure decay was segmented into two components: an exponential decay that reflects the compliance characteristics of the large arteries and an oscillatory diastolic waveform generated principally by pulse-wave reflections from small arteries and arterioles. RESULTS: Resting heart rate was higher in smokers than nonsmokers, mean +/- SD (66 +/- 9 versus 60 +/- 10; P < 0.05). Systolic, diastolic, and mean arterial pressures were lower in smokers compared with nonsmokers (P < 0.01 for all). No differences in cardiac output, large artery compliance, or systemic vascular resistance estimates where apparent between groups. A decrease in the amplitude and duration of the diastolic wave, produced by peripheral pulse-wave reflections in the arterial system, was found in smokers compared with nonsmokers (0.04 +/- 0.02 versus 0.7 +/- 0.03; P < 0.001). CONCLUSIONS: Quantitative changes in the arterial waveform were found in long-term smokers compared with nonsmoking control subjects. The altered arterial wave shape marks the presence of abnormal structure or tone in the peripheral vasculature that affects pulsatile arterial function. This measure of vascular injury is detectable at a preclinical stage and may relate to the subsequent risk of morbid events in chronic smokers and aid in clinical risk stratification.

Validation study of a new transit time ultrasonic flow probe for continuous great vessel measurements.

Continuous measurement of cardiac output is important during experimental and clinical cardiac surgery as an indicator of ventricular function. Previous flow probes underestimated flow secondary to position and flow (S-series probes; Transonic Systems, Inc., Ithaca, NY), required frequent calibrations (electromagnetic), and were cumbersome to use. The new A-series probe (ASP) by Transonic Systems, Inc., uses a new X method of ultrasonic illumination insensitive to perturbations in flow. The ASPs were found to be accurate during in vitro studies, but have not been validated in vivo. Six anesthetized pigs were instrumented for right atrium to left atrium bypass, and ASPs were placed on the ascending aorta and pulmonary artery. Baseline measurements included aortic (Ao) and pulmonic flow (P), and thermodilution (Td) cardiac output. Animals then were placed on right heart bypass, and flow was randomly varied from 1 to 6 L/min, and Ao flow was recorded. In addition, ASPs were rotated and their direction reversed. After data collection, the occlusive roller pump (RP) was calibrated using a timed collection method. Calibrated RP flows were plotted versus ASP flows, and regression was applied. There was no difference between mean Ao, P, and Td cardiac outputs at baseline. In addition, changes in position and direction of the probe did not affect measurement of flow. The ASPs showed a highly linear correlation with RP ([r = 0.98, p < 0.01] ASP[L/min] = 0.98 RP-0.032). During laminar flow states, ASPs are accurate and insensitive to position on the great vessels.

Evaluación ecocardiográfica de la función cardíaca en pacientes con insuficiencia renal crónica

Con el fin de evaluar la función cardíaca en pacientes con insificiencia renal crónica (IRC) y el efecto que sobre ella pueden ejercer los medicamentos, se medieron parámetros ecocardiográficos modo M y bidimensionales en 27 pacientes con insuficiencia renal crónica (IRC) terminal durante un período de observación de dos años. Nueve pacientes recibieron tratamiento médico solamente (grupo prediálisis), 10 entraron en programa hemodiálisis crónica (grupo diálisis) y ocho recibieron trasplante renal (grupo trasplante). Se encontró hipertrofia ventricular izquierda con predominio septal e hipoquinesia de este segmento en los tres grupos, con predominios de 11.5ñ3, 13.4ñ 12.8ñ3 en los grupos de prediálisis, diálisis y trasplante respectivamente. El diámetro sistólico en los pacientes en prediálisis mostró diferencias significativas con los pacientes (42.8ñ9 vs 35.4ñ7, p<0.05), asociado con disminución correspondiente de la movilidad de la pared posterior. El promedio de la fracción de eyección en los tres grupos se observó dentro de los límites normales bajos: 44.8ñ14.8, 53.2ñ12.6 y 54.2ñ10.7 respectivamente. La masa ventricular izquierda se encontró aumentada en la mayoría de los pacientes: 423.1ñ195, 414.8ñ90 y 377.5ñ127 respectivamente. El tamaño de la arteria pulmonar fue significativamente mayor en el grupo prediálisis: 28.3ñ6 vs 24.1ñ4 (p<0.050), 23.7ñ5 respectivamente. El índice PPE/TEVD de los intervalos sistólicos del ventrículo derecho se observó significativamente prolongado en el grupo prediálisis: 0.268ñ0.14, 0.256ñ0.13 y 0.169ñ0.07 respectivamente. El aumento de la masa ventricular por encima de 400 g, el deterioro de la función sistolica y la dilatación de la arteria pulmonar con signos de hipertensión pulmonar caracterizan a los pacientes renales terminales no intervenidos. En los pacientes trasplantados persiste tendencia a hipertrofia con predominio septal, cuya patología concomitante más frecuente es la hipertension arterial.