Usefulness of unipolar electrograms to detect isthmus block after radiofrequency ablation of typical atrial flutter.

BACKGROUND: RS morphology of the unipolar electrogram is associated with propagation of the wave front through the exploring electrode, whereas positive uniphasic (R) unipolar electrograms are characteristic of the end of activation. METHODS AND RESULTS: Unipolar electrograms were recorded in 45 consecutive patients with atrial flutter who were undergoing radiofrequency ablation (RFA). Bidirectional cavotricuspid isthmus (CTI) block was achieved in 44 patients. The unipolar electrogram obtained before RFA at the low anterolateral right atrium during coronary sinus pacing changed from RS, rS, or QS to R or Rs in all patients after clockwise CTI block was obtained. The morphology of unipolar electrograms recorded close to the coronary sinus during pacing from the low anterolateral right atrium changed from RS or rS to R or Rs in all but 4 patients after counterclockwise CTI block. In the patient in whom CTI block was not achieved, the RS morphology of the unipolar electrogram remained unchanged. In 18 patients, the results of the RFA were assessed with only the unipolar electrogram. The unipolar electrogram correctly predicted 100% and 89% of the cases of clockwise and counterclockwise CTI block, respectively. CONCLUSIONS: The creation of CTI block is associated with an easily detectable loss of negative components and development of an R or Rs pattern of the unipolar electrogram recorded close to the ablation line while pacing at the opposite side of the CTI.

Effects of dobutamine on Doppler echocardiographic indexes of aortic stenosis.

OBJECTIVES: This study sought to assess the diagnostic implications of the flow dependence of Doppler echocardiographic indexes of aortic valve stenosis. BACKGROUND: Although valve area has been shown to change with alterations in flow rate, the diagnostic consequences of this phenomenon remain unknown. Valve resistance has been suggested as a more stable index for evaluating aortic stenosis. METHODS: A low dose dobutamine protocol was performed in 35 patients with aortic stenosis. Hemodynamic indexes were obtained by Doppler echocardiography at baseline and at each dobutamine dose. RESULTS: As a result of the shortening of the systolic ejection period, flow increased from (mean +/- SD) 164 +/- 48 to 229 +/- 102 ml/s (p < 0.0001). At peak flow, valve area increased by 28% (from 0.5 +/- 0.2 to 0.6 +/- 0.3 cm2, p < 0.0001), whereas valve resistance decreased by 4% (from 498 +/- 252 to 459 +/- 222 dynes.s.cm-5, p = 0.04). This observed change in resistance was smaller than that for valve area (p < 0.01). The flow dependence of valve area varied among individual patients (p < 0.0001). Multivariate analysis identified calcific degenerative etiology (beta 0.29, p = 0.002), left ventricular velocity of fiber shortening (beta 0.22, p = 0.01), baseline flow (beta -0.28, p = 0.04) and amount of flow increased induced by dobutamine (beta 0.90, p < 0.0001) as factors related to valve area flow dependence. CONCLUSIONS: Although all Doppler echocardiographic indexes of aortic stenosis are affected by flow, valve resistance is more stable than valve area under dobutamine-induced hemodynamic changes. Baseline valve area may be unreliable in patients with calcific degenerative aortic stenosis and low output states.

[Massive myocardial infiltration by lymphoma of tonsilar origin simulating left ventricular hypertrophy: diagnosis using echocardiography]. / Infiltración miocárdica masiva por linfoma de origen amigdalar que simula hipertrofia ventricular izquierda: diagnóstico mediante ecocardiografía.

We present the first described case in the literature of isolated left anterior hemiblock, in the setting of massive myocardial invasion by a primary tonsilar lymphoma. Such process evolved with a morphologic pattern mimicking left ventricular hypertrophy of unequal distribution. An hemodynamic behaviour of an infiltrative cardiomyopathy, with both systolic and diastolic important ventricular dysfunction, was observed. An early presumptive diagnosis of severe lymphomatous myocardial invasion was established by echocardiography. The pathologic examination confirmed it subsequently.

[The usefulness of transesophageal echocardiography in general intensive care units]. / Utilidad de la ecocardiografía transesofágica en las unidades de cuidados intensivos generales.

BACKGROUND AND OBJECTIVES: It's well known the utility of transesophageal echocardiography in the evaluation of cardiological patients that are critically ill. However, there is less experience about this usefulness in non-cardiological critically ill patients. METHODS: To assess the utility and safety of the method we analyzed 51 correlative studies of patients admitted to our general Intensive Care Unit. Forty-seven patients (92%) were on mechanical ventilation and in 24 patients (47%) continuous assessment of the hemodynamic variables were available. RESULTS: The most frequent diagnoses on admission were sepsis (23.5%) and shock status (17.6%). The indications were: suspicion of endocarditis (15 patients), hemodynamic instability (11 cases), cardiac source of embolus (10), suspicion of cardiac tamponade (4), suspicion of aortic dissection (4) and other causes in 7. The study confirmed the clinical suspicion in 31 cases (60.8%), excluded it in 15 (29.4%) and established a new, non-suspected, diagnosis in 5 patients (9.8%). There were major diagnostic changes in 16 patients (31.6%) and minor changes in 17 (33.3%) comparing the results of the transesophageal and transthoracic approaches. It was also assessed the influence of the result on the clinical management of the patient: in 32 cases (62.8%) there were a significant change in the treatment; in 5 patients (9.8%) cardiac surgery was prompted by echocardiography. Only in 3 patients hypertensive reactions and tachycardia were detected, without posterior consequences. CONCLUSIONS: Transesophageal echocardiography can be safely performed and has a definite role in the diagnosis (showing sometimes non-suspected abnormalities) and management of non-cardiological critically ill patients.

[Usefulness of transesophageal echocardiography in the critical patient]. / Utilidad de la ecocardiografía transesofágica en el paciente crítico.

To assess the usefulness and safety of transesophageal echocardiography in critically ill patients, we analysed the transesophageal echocardiography studies in 60 of such cases (age: 58 +/- 11 and 38 males). Every patient underwent a previous transthoracic echocardiogram, that was considered inadequate for diagnostic purposes. Thirty patients (50%), were on mechanical ventilation and 17 patients (28%) showed hypotension and/or shock. Forty patients (66%) were at special care units and in 31 (52%) of them, pulmonary and systemic pressures, and continuous analysis of venous pressure of oxygen were available. Indications for study were: 17 patients with clinical suspicion of aortic dissection (confirmed in 5 cases): 9 patients infective endocarditis (4 cases showed valvular vegetations); 6 patients with mitral prosthesis dysfunction (confirmed in 4 cases); complicated acute myocardial infarction (MI) in 8 patients (2 cases with mitral insufficiency, 3 with left ventricular dysfunction, 1 with right ventricular MI, 1 with left ventricular pseudoaneurysm and other with isolated inferior MI); in 11 patients the study was performed to evaluate the result of cardiac transplantation immediately (< 4 h) and it showed 2 cases of left ventricular dysfunction; 3 patients were studied for severe cardiac dysfunction of unknown etiology (a dilated cardiomyopathy was confirmed in one and ruled out in the other, and one patient showed signs of restrictive situation); there were other causes in the rest. The procedure could be completely performed in all cases. In conclusion in critically ill patients the transesophageal echocardiography has a great usefulness and minimal complications.

[The echocardiographic assessment of wall regurgitant jets in prosthetic mitral valves: the superiority of multiplanar transesophageal sections over standard sections]. / Valoración ecocardiográfica de los jets regurgitantes de pared en válvulas protésicas mitrales: superioridad de las secciones transesofágicas multiplanares sobre las secciones estándares.

OBJECTIVES: The purpose of this study was to determine whether multiplanar (MP) transesophageal echocardiographic views were superior to standard views (ST), in the evaluation of mitral prosthesis regurgitation (MR), particularly in presence of wall regurgitant jets. METHODS: We studied all mitral prostheses (n = 43) in which pathological mitral regurgitation had been detected by multiplanar TEE between January 1993 and March 1994. Regurgitant prostheses were classified in two groups according to the presence of wall regurgitant jets and maximum turbulent color flow areas (Amax.) were measured on standard (0 and 90 degrees) and MP (0 to 180 degrees) views. RESULTS: The Amax. detected on ST views were 5.80 +/- 4.60 cm2 and on MP 7.42 +/- 5.13 cm2. Student's test was used to compare both areas and significant differences were found: 1.61 cm2; 95% confidence interval from 0.94 to 2.28 cm2; p = 0.000025. The sample was divided in two groups, A (n = 33): with wall jets and B (n = 10): without wall jets. The Amax. for group A was 5.64 +/- 4.30 cm2 in ST views, and 7.51 +/- 5.12 cm2 in MP. The difference was statistically significant: 1.86 cm2, 95% c.i. from 1.04 to 2.68 cm2; p = 0.00009. Differences for group B were also statistically significant: 0.68 cm2; p = 0.0172. MP views detected a bigger regurgitant area in 26 of the 43 cases (60%). The difference between ST and MP views was significantly bigger for group A than for group B: mean 1.18 cm2; p = 0.0176. MP views detected a severer degree of MR, classified as mild moderate and severe according to the color flow area, than ST views in 8 patients. All of them had wall regurgitant jets. Three had been considered normal on ST views. CONCLUSION: We conclude that MP transesophageal views are significantly superior to ST in the assessment of regurgitant prosthetic mitral valves, particularly in presence of wall regurgitant jets. Our data strongly suggest that multiplanar TEE is the procedure of choice in the assessment of wall regurgitant mitral prostheses.

[Transesophageal echocardiography assessment of regurgitant jets of eccentric geometry in mitral valve prosthesis: superiority of multiplanar sections over standard sections]. / Avaliação por ecocardiografia transesofágica dos jactos regurgitantes de geometria excêntrica em válvulas protésicas mitrais: superioridade das secções de corte multiplanares sobre as secções standard.

OBJECTIVE: The purpose of this study was to determine whether multiplanar (MP) transesophageal echocardiographic views were superior to standard views (ST) at 0 degree and 90 degrees in the evaluation of mitral prosthesis regurgitation (MR), particularly in presence of wall regurgitant jets. DESIGN: Comparison between MP and ST views in the evaluation of mitral prosthesis regurgitation. SETTING: Laboratory of Echocardiography of the General Hospital Gregorio Marañon. MATERIAL AND METHODS: Study of all mitral prostheses in which pathological mitral regurgitation had been detected by multiplanar TEE, between January 1993 and March 1994. Regurgitation prosthesis were classified in two groups according to the presence of wall regurgitation jets and maximum turbulent color flow areas (MAX) were measured on standard (0 degree and 90 degrees) and MP (0 degree to 180 degrees) views. The sample was divided in two groups, A (n = 33): with wall jets and B (n = 10): without wall jets. Students' t test was used to compare both areas using a 95% confidence interval (95% c.i.). RESULTS: MAX detected on ST views were of 5.80 +/- 4.60 cm2 and on MP were of 7.42 +/- 5.13 cm2 being the difference statistically significant: 1.61 cm2, 95% c.i. from 0.94 to 2.28 cm2, p = 0.000025. MAX for group A was of 5.64 +/- 4.30 cm2 in ST views and of 7.51 +/- 5.12 cm2 in MP views, being the difference 1.86 cm2, 95% c.i. from 1.04 to 2.68; p = 0.00009. Differences for group B were also statistically significant: 0.68 cm2, p = 0.0176. Mitral regurgitation (MR) was classified as mild, moderate and severe according to the color flow area. MP views detected a severer degree of MR than ST views in 8 patients, all of them with wall regurgitation jets. Three of these cases had been considered normal on ST views. CONCLUSIONS: Multiplanar transesophageal views are significantly superior to standard views in the assessment of regurgitant prosthetic mitral valves, particularly in presence of wall regurgitant jets. Our data strongly suggest that multiplanar TEE is the procedure of choice in the assessment of wall regurgitant mitral prostheses.

Pulmonary venous flow in hypertrophic cardiomyopathy as assessed by the transoesophageal approach. The additive value of pulmonary venous flow and left atrial size variables in estimating the mitral inflow pattern in hypertrophic cardiomyopathy.

AIMS: This study was conducted to assess the characteristics of the pattern of pulmonary venous flow and to document the interaction of this flow and left atrial function with the pattern of mitral inflow in hypertrophic cardiomyopathy. METHODS AND RESULTS: Pulmonary venous and mitral flows were evaluated by the transoesophageal approach in 80 patients with hypertrophic cardiomyopathy. Left atrial size and function were measured by the transthoracic approach. Their values were compared with those obtained from 35 normal controls. Twelve patients showed significant (> 2+) mitral regurgitation. As a group, hypertrophic cardiomyopathy patients showed increased atrial reversal flow and longer deceleration time of the diastolic wave, but a wide variability of pulmonary venous flow patterns were observed. Thirty patients (37.5%) had pseudonormal mitral flow patterns. Stepwise multilinear regression analysis identified the ratio of systolic to diastolic pulmonary venous flow velocity, the ratio of velocity-time integrals of both flow waves at atrial contraction, the left atrial minimal volume and the systolic fraction as independent predictive variables of the mitral E/A wave velocity ratio (r = 0.82). By logistic regression, the former three variables were selected as independent predictive covariates of a pseudonormal mitral flow pattern (sensitivity: 83%, specificity: 90%). The ratio of velocity-time integrals of both atrial waves was the most important predictive variable in both analyses. CONCLUSIONS: The observed variability in the configuration of pulmonary venous flow velocity waveform is related to what occurs in transmitral flow in patients with hypertrophic cardiomyopathy. Significant mitral regurgitation is not an independent correlate of pseudonormal mitral inflow patterns in these patients. Our results further emphasize the complementary, additive value of the pulmonary venous flow velocity pattern and left atrial size in the interpretation of the mitral flow velocity pattern, and indirectly suggest the underlying increased left ventricular filling pressures of patients with hypertrophic cardiomyopathy and pseudonormal mitral flow patterns.

Diagnostic value of two-dimensional echocardiography in cardiac hydatid disease.

Echinococcal infection of the heart is rare. The preoperative findings, with special attention to two-dimensional echocardiography (2DE), of six patients with cardiac echinococcosis and their surgical and pathological correlations are reported. Cardiac hydatid cysts (HCs) were located in the cardiac apex in three patients, in the upper part of the interventricular septum extending towards the anterior aspect of the heart in one and in the postero-superior right atrial wall in another patient. The remaining patient had multiple intrapericardial cysts. In three patients the cysts presented as well defined, rounded, echolucent masses within the myocardial wall bulging into the cardiac chambers. In two patients, the cysts had ruptured into a cardiac chamber with loss of the characteristic 'cystic' appearance; these cysts presented as an echogenic or solid mass protruding into a cardiac chamber. Finally, another patient had one HC with echolucent appearance and another HC in a different location with echogenic appearance; this last cyst corresponded to a degenerated HC. In two cases the cyst showed a loculated internal aspect. In one patient the myocardial segment involved by the cyst had a dyskinetic movement. In all six patients, 2DE accurately demonstrated the location and morphological details of the cardiac cysts, permitted recognition of the ruptured and/or degenerated cysts and was superior to thoracic computed tomography and angiography in the preoperative assessment of these patients. Nuclear magnetic resonance imaging (one patient) gave no further information to that obtained by 2DE. We conclude that 2DE is the technique of choice for an early diagnosis of this rare entity.

Left atrial appendage Doppler flow patterns: implications on thrombus formation.

The characteristics and clinical implications of left atrial appendage (LAA) flow have not been clearly analyzed. Thirty-nine consecutive patients underwent a transesophageal echocardiographic (TEE) color Doppler study to correlate the LAA pulsed Doppler flow pattern with echocardiographic variables and the cardiac rhythm of each patient. Three different LAA flow patterns were identified. Type I flow, characterized by a biphasic pattern (waves of filling and emptying), was found in 17 patients, all in sinus rhythm; it was not associated with LAA spontaneous contrast or thrombus. Mean peak velocities of the filling and emptying waves were, respectively: 28 +/- 12 cm/sec and 31 +/- 9 cm/sec. Type II sawtooth active flow (eight patients) (mean peak velocity: 49 +/- 12 cm/sec) was only detected in atrial fibrillation (AF) and dilated LAA (LAA area: 421 +/- 40 mm2) but without thrombus or significant LAA spontaneous echocardiographic contrast. Type III flow pattern was noted in 14 patients with AF and a very dilated LAA (LAA area: 619 +/- 96 mm2). This flow pattern was characterized by the absence of identifiable flow waves and was associated with the presence of LAA spontaneous contrast; the majority (six of seven) had evidence of thrombus. We concluded that the LAA is a dynamic structure in which TEE study identified three flow patterns with different implications. AF is associated with two LAA flow types (II and III) with a larger LAA size as well as a higher incidence of LAA clots in type III flow.