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Biomedical subjects

J C da Cunha

Publications and source records attributed to J C da Cunha.

10 recordsLinked to original sources
PubMed2001

[Time's paradigm in primary angioplasty].

The use of primary angioplasty in the treatment of acute myocardial infarction (AMI), as opposed to fibrinolysis, is well established, as long as performed by an experienced team. The benefits are "time-dependent", hense the rational for the sentence "Time is Muscle". It is very important to assess the time factor, mainly if the therapeutic option is primary angioplasty, since it is necessary to set up a full range of conditions related to this type of specific treatment (human, material and logistical). In the current study was analysed the in and out of hospital time sequence of 99 patients with AMI that underwent primary PTCA during the year of 1999. The main goal was to assess if the performance of this procedure outside regular working hours could have any significant impact on the "time of in-hospital ischemia". The different time durations were prospectively recorded according to a protocol that was previously established and filled for each patient by the lab team. The authors conclude that: a) the average in-hospital time delay in the treatment of AMI by PTCA was not significantly influenced by the fact that the procedure was performed outside the regular working hours of the lab; b) the main component of the "ischemic in hospital time" corresponds to the time between the patient's admission and the decision making time for PTCA. Although the average decision making time for PTCA is too long and must be optimized, the average total in hospital ischemic time (99-105 minutes) compares favorably with other previous reports in the literature.

Aged↗
PubMed2001

Pulmonary transvalvular and venous flows in the estimation of left ventricular diastolic pressures. A comparative Doppler-catheterization study.

OBJECTIVES: To evaluate the association between patterns of pulmonary transvalvular and venous flows in patients with ischemic heart disease, assessed by Doppler echocardiography, and invasive measurements of left ventricular (LV) diastolic pressures. POPULATION: Thirty-seven patients with clinical diagnosis or suspicion of coronary heart disease and referred for coronary angiography; all were in sinus rhythm, and had no known valvular heart or chronic pulmonary disease. METHODS: The following were recorded during transthoracic Doppler echocardiography: acceleration time (AT) and total ejection time (ET) of right ventricular outflow; duration of the flow at atrial contraction (a duration) and duration of the "A" wave of mitral inflow (A duration). These data were correlated with the values of LV filling pressures previously obtained by cardiac catheterization. RESULTS: We found a significant correlation of LV end-diastolic pressures with the difference a-A duration (r = 0.75; p < 0.001) and also with the ratio AT/ET (r = -0.73;.

Adult↗
PubMed1996

Methyl parathion activation by a partially purified rat brain fraction.

Organophosphorus pesticides are one of the most commonly used insecticide classes. They act through a potent inhibition of acetylcholinesterase (AChE). Many of them must undergo transformation into the corresponding oxon analogs to inhibit AChE. This study showed that a brain tissue subfraction transformed methyl parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) in vitro. Methyl parathion activation was assayed by solvent extraction of the products followed by HPLC and GC-MS analyses and, indirectly, by the inhibition of AChE present in the incubation mixture. The lack of impairment of AChE after 2 h of incubation of the brain subfraction with methyl parathion and, alternatively, with NADPH, CO, SKF 525-A, piperonyl butoxide or nitrogen indicated that this brain subfraction transformed methyl parathion without the involvement of a mixed-function oxidative pathway. The results from HPLC analysis did not show a peak corresponding to methyl paraoxon (O,O-dimethyl O-p-nitrophenylphosphate), but showed the production of an unidentified peak which eluted nearby standard methyl parathion (retention times of 10.65 and 8.86 min, respectively). GC-MS analysis suggested that the unidentified product could be a methyl parathion isomer.

Acetylcholinesterase↗
PubMed1994

[Permanent pacing in childhood: a review of 11 years of experience].

STUDY OBJECTIVE: To review our eleven year experience in the implantation and follow-up of permanent Pacemakers in the paediatric age group. DESIGN: Retrospective study. SETTING: Children submitted to permanent cardiac Pacing implantation and accompanied in the Pacing Center of the Hospital de Santa Maria. PATIENTS: Children from both sexes, aged from neonate to 14 years old, with brady-dysrhythmia and indication for permanent cardiac Pacing implantation. MATERIAL AND METHODS: From November 1980 to September 1991, 16 children had permanent Pacemaker implantation. We describe the clinical and electrocardiographic characteristics of the population, mode of Pacing used, technical data from the implantation and evolution. RESULTS: One children died due to associated cardiac defect not related to the Pacemaker. The other 15 children remain in follow-up with normofunctioning Pacemakers and free of symptoms. We had to perform 11 reinterventions in 8 children due to generator or electrode problems (28,2 months reintervention interval). CONCLUSIONS: Improvements in Pacemaker technology and a careful technique of implantation can significantly reduce the morbidity associated to permanent pacemaker implantation in this age group.

Adolescent↗
PubMed1990

[The use of Holter electrocardiography in permanent pacemaker users].

The authors selected 37 permanent pacemaker patients followed for eleven successive months, with symptomatology eventually related to the pacing system. An Holter ambulatory monitorization was performed to all of them during 24 hours. Twenty one had single chamber systems and the others double chamber. Twelve malfunctions were found in ten patients. Six due to "undersensing", 4 related to "oversensing", and 2 from loss of capture. Two patients had tachycardia pacemaker mediated. An inadequate mode of pacing was found in other two cases. Fifteen rhythm disturbances not related to the pacemaker systems were registered in thirteen patients: supra-ventricular in 9; ventricular greater than or equal to 3 degree of lown in 5; and 2nd degree A.V.B. Mobitz type I in one case. Four patients were submitted to surgical intervention in order to modify the mode of pacing. It was also necessary to reprogram ten patients. The Holter Ambulatory Electrocardiography revealed to be an important diagnostic method for the detection of intermittent malfunction of pacing systems. The occasional changes of cardiac rhythm not linked with pacing were also revealed.

Adult↗
PubMed1990

[Atrial pacing in the evaluation of coronary disease].

In order to assess the value of atrial pacing in the diagnosis of myocardial ischemia, 23 patients (mean age 53 +/- 8 years), submitted to coronary angiography, were studied. Atrial Pacing at incremental frequencies was performed until the appearance of electrocardiographic changes (ST segment depression) and/or typical anginal pain. The highest frequency of stimulation was 160/min. The test was negative in four of five patients (80%) without significant obstructive coronary artery disease. Atrial pacing test was positive in 17 of 18 patients (94%) with abnormal angiography. The authors concluded that clinical and ECG abnormalities induced by atrial pacing seems to be correct indicators for the diagnosis of myocardial ischemia. This test can be an useful alternative in patients unable to perform a conclusive stress test.

Cardiac Pacing, Artificial↗
PubMed1990

[Atrial pacing and the exercise test in the evaluation of coronary disease. A comparative study].

OBJECTIVE: to compare the relative value of Atrial Pacing and Exercise Electrocardiography in the diagnosis of Myocardial Ischaemia. DESIGN: prospective study in patients referred for coronary cineangiography. SETTING: Cineangiography and Ergonometry Departments of Cardiology Service. Santa Maria Hospital. PATIENTS: 16 patients (mean age 52.4 +/- 6.3), 13 males and 3 females. All were submitted to Atrial Pacing, Exercise Test and Coronariography. RESULTS: both tests were concordant in all cases but one, with negative Atrial Pacing, positive Exercise Test and negative Coronariography. CONCLUSIONS: Atrial Pacing compares favourably with Exercise Test in the diagnosis of Coronary Ischaemic Disease. It may constitute a valid alternative in patients unable to perform a conclusive Exercise Test.

Cardiac Pacing, Artificial↗
PubMedDate not supplied

[Measles].

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Child↗