José Nogueira Paes Júnior

Ressincronização ventricular: comparando os marcapassos biventriculares com os marcapassos bifocais de ventrículo direito

OBJECTIVE To analyze the conventional biventricular pacing (BV) and the bifocal (BF) right ventricular (RV) pacing, and to perform a comparative analysis of these two techniques in relation to clinical, functional and echocardiographic parameters in a population without the exclusion criteria of the major studies. METHODS A prospective non-randomized analysis of 36 patients undergoing surgery for multisite pacemaker implantation due to QRS > or =130 ms, severe left ventricular dysfunction, and NYHA functional class III or ambulatory class IV congestive heart failure was performed. RESULTS Favorable results of resynchronization were obtained with both techniques, with no significant differences in the comparison of the two groups, except for a higher QRS narrowing in the BV group, and a trend of a lower number or hospital admissions in the BV group. When the groups were analyzed separately and compared before and after the procedures, we observed that improvement was much more significant in the biventricular group, as were the more statistically relevant rates. CONCLUSION Cardiac resynchronization therapy proved to be an efficient therapy in both groups analyzed, although with more significant outcomes in the biventricular group.

Internal thoracic artery graft (ITAG): patency and functional status at rest and during dobutamine-stress echocardiography

BACKGROUND: The patent internal thoracic artery graft (ITAG) usually has a diastolic fraction (DF) > 50% of the flow. The functional assessment can be evaluated by the coronary reserve index (CRI). OBJECTIVE: The objective was to evaluate the patency and functional status of the ITAG through echocardiography and Doppler. METHODS: Data from sixty-six patients who underwent dobutamine-stress echocardiography (DSE) were prospectively collected and analyzed. Group I (GI) had 49 ITAG without stenosis, Group II (GII), 10 ITAG with significant stenosis (> 50% and 50%, it was observed in 49 ITAG (GI= 40, GII= 8 and GIII= 1) at rest and in 61 ITAG (GI=49, GII=10 and GIII=2) during DSE. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were respectively, 81%, 86%, 98%, 35% and 82%, and 100%, at rest and 71%, 97%, 100% and 97% in the DSE. The ITAG with DF>50% at rest were patent and the ones with DF 1.8 for a good functional status, it was observed in 42 ITAG (39 from GI, 2 from GII and 1 from GIII), determining sensitivity=79%, specificity=85.7%, PPV=94%, NPV=59% and accuracy= 80.9%. The CRI in GI was higher (p= 0.02) than in GII or GIII. CONCLUSION: In our study, the non-invasive assessment of the ITAG was effective to verify the patency and the functional status.

Acute myocardial infarction: predictors of mortality at a public hospital in the city of Fortaleza, Ceará state

OBJECTIVE: To identify the clinical and demographic predictors of in-hospital mortality in acute myocardial infarction with elevation of the ST segment in a public hospital, in the city of Fortaleza, Ceara state, Brazil. METHODS: A retrospective study of 373 patients experiencing their first episode of acute myocardial infarction was carried out. Of the study patients, 289 were discharged from the hospital (group A) and 84 died (group B). Both groups were analyzed regarding: sex; age; time elapsed from the beginning of the symptoms of myocardial infarction to assistance at the hospital; use of streptokinase; risk factors for atherosclerosis; electrocardiographic location of myocardial infarct; and Killip functional class. RESULTS: In a univariate analysis, group B had a greater proportion of the following parameters as compared with group A: non-Killip I functional class; diabetes; age >70 years; infarction of the inferior wall associated with right ventricular impairment; time between symptom onset and treatment at the hospital >12 h; anteroseptal or extensive anterior infarction; no use of streptokinase; and no tobacco use. In a multivariate logistic regression analysis, only non-Killip I functional class, diabetes, and age >70 years persisted as independent factors for death. CONCLUSION: Non-Killip I functional class, diabetes, and age >70 years were independent predictors of mortality in acute myocardial infarction with elevation of the ST segment.

Tetralogy of Fallot and hypertrophic cardiomyopathy: a rare association

Tetralogy of Fallot is known as the most common cyanotic congenital heart disease and has a prevalence of 10% of all congenital heart diseases. Although many other heart anomalies may coexist, the association of tetralogy of Fallot and hypertrophic cardiomyopathy is extremely rare. We report this association in a 15-month-old female, cyanotic since birth, in her first hospital admission for diagnosis and treatment of recurring cyanotic crises. In addition, a review of the literature and of the problems related to the treatment is provided.

Coronary Flow Velocity Reserve during Dobutamine Stress Echocardiography

Background A coronary flow velocity reserve (CFVR) ≥ 2 is adequate to infer a favorable prognosis or the absence of significant coronary artery disease. Objective To identify parameters which are relevant to obtain CFVR (adequate or inadequate) in the left anterior descending coronary artery (LAD) during dobutamine stress echocardiography (DSE). Methods 100 patients referred for detection of myocardial ischemia by DSE were evaluated; they were instructed to discontinue the use of β-blockers 72 hours prior to the test. CFVR was calculated as a ratio of the diastolic peak velocity (cm/s) (DPV) on DSE (DPV-DSE) to baseline DPV at rest (DPV-Rest). In group I, CFVR was < 2 and, in group II, CFVR was ≥ 2. The Fishers exact test and Students t test were used for the statistical analyses. P values < 0.05 were considered statistically significant. Results At rest, the time (in seconds) to obtain Doppler in LAD in groups I and II was not different (53±31 vs. 45±32; p=0.23). During DSE, LAD was recorded in 92 patients. Group I patients were older (65.9±9.3 vs. 61.2±10.8 years; p=0.04), had lower ejection fraction (61±10 vs. 66±6%; p=0.005), higher DPV-Rest (36.81±08 vs. 25.63 ± 06cm/s; p<0.0001) and lower CFVR (1.67 ± 0.24 vs. 2.53 ± 0.57; p<0.0001), but no difference was observed regarding DPVDSE (61.40±16 vs. 64.23±16cm/s; p=0.42). β-blocker discontinuation was associated with a 4-fold higher chance of a CFVR < 2 (OR= 4; 95% CI [1.171-13.63], p=0.027). Conclusion DPV-Rest was the main parameter to determine an adequate CFVR. β-blocker discontinuation was significantly associated with inadequate CFVR. The high feasibility and the time to record the LAD corroborate the use of this methodology.

Prognostic Value of Coronary Flow Reserve Obtained on Dobutamine Stress Echocardiography and its Correlation with Target Heart Rate

Background Normal coronary flow velocity reserve (CFVR) (≥ 2) obtained in the left anterior descending coronary artery (LAD) from transthoracic echocardiography is associated with a good prognosis, but there is no study correlating CFVR with submaximal target heart rate (HR). Objective To evaluate the prognostic value of CFVR obtained in the LAD of patients with preserved (>50%) left ventricular ejection fraction (LVEF) who completed a dobutamine stress echocardiography (DSE), considering target HR. Methods Prospective study of patients with preserved LVEF and CFVR obtained in the LAD who completed DSE. In Group I (GI = 31), normal CFVR was obtained before achieving target HR, and, in Group II (GII = 28), after that. Group III (G III=24) reached target HR, but CFVR was abnormal. Death, acute coronary insufficiency, coronary intervention, coronary angiography without further intervention, and hospitalization were considered events. Results In 28 ± 4 months, there were 18 (21.6%) events: 6% (2/31) in GI, 18% (5/28) in GII, and 46% (11/24) in GIII. There were 4 (4.8%) deaths, 6 (7.2%) coronary interventions and 8 (9.6%) coronary angiographies without further intervention. In event-free survival by regression analysis, GIII had more events than GI (p < 0.001) and GII (p < 0.045), with no difference between GI and GII (p = 0.160). After adjustment, the only difference was between GIII and GI (p = 0.012). Conclusion In patients with preserved LVEF and who completed their DSE, normal CFVR obtained before achieving target HR was associated with better prognosis.

Steal of blood flow from the vertebral artery to the internal thoracic artery anastomosed to the coronary artery

The left vertebral and internal thoracic arteries are branches of the left subclavian artery which, under physiological conditions, exhibit antegrade flow direction. On Doppler evaluation, the internal thoracic artery (ITA) flow shows a predominance of systolic component, but when anastomosed to the left coronary arteries, the prevalence of the diastolic component is usual. This predominance can become exacerbated and a situation that increases oxygen consumption by the myocardium can occur, such as what happens during dobutamine stress echocardiography, when the systolic component can be suppressed and the diastolic becomes the only component of the cardiac cycle. The two-dimensional and Doppler imaging allows anatomical assessment of arteries and the verification of normal and pathological flow patterns. Thus, the flow direction reversal of an artery can be compatible with steal of blood flow and an exacerbation of the diastolic component of the anastomosed internal thoracic artery (AITA) at Doppler may indicate good functional status of the vessel1-3. Occlusion of the left subclavian artery determines impairment of blood supply to the left arm, but the steal of blood flow from the left vertebral artery may improve limb perfusion. When the subclavian artery occlusion occurs in cases with ITA anastomosed to the left coronary arteries, the direction of the post-stenotic flow in symptomatic patients is variable and can be reverse in the vertebral and internal thoracic arteries4, have no reverse component5, be reverse only in ITA6 or, as in our patient, show preferential reverse flow from the left vertebral artery to the ITA.