[Atypical sinus node dysfunction. Usefulness of implantable Holter. A case report]. / Disfunción sinusal atípica. Utilidad del Holter implantable. A propósito de un caso.

We present an 84 year-old female patient with repeated syncopes/presyncopes in the last nine years. All diagnosis tests were negative, including ECG, 24-hour Holter, tilt table test and EP study. Therefore, a subcutaneous insertable loop recorder was implanted (Reveal). The recording of three episodes showed the association of presyncope with the onset of atrial fibrilation and, in two syncopes, with an atrial pause between AF episodes. Probably an abnormal prolonged sinus node recovery time (more than 6 s) allowed AF to restart before the sinus rhythm.

[Adverse effects of dobutamine stress echocardiography]. / Efectos secundarios de la ecocardiografía de estrés con dobutamina.

OBJECTIVES: To study the side effects of dobutamine echocardiography and to define the protocol with less side effects. PATIENTS AND METHODS: Since June 1992 to November 1994 dobutamine echocardiography was performed on two different groups of patients. In the first, the test was preoperatively done to evaluate the surgical risk. The remaining were patients with angina. Dobutamine was started at a dose of 5 micrograms/kg/min and increased up to a total dose of 40 micrograms/kg/min. Since March 1993 atropine was added if the heart rate was under 90 beats/min. RESULTS: One hundred and forty one patients were included (76 for a preoperatory appraisal and 65 with angina). Echocardiography test was not performed on 3 patients (2 with pulmonary disease and 1 with a therapeutic neumothorax). Among the remaining 138 patients, side effects appeared in 53 patients (38%) and test had to be prematurely interrupted in 11 (8%) of them. Side effects presented during the test in 9 (7%) although it could be finished and at the end of the test in 33 (24%). The most frequent side effects were arrhythmias that appeared in 28 patients (20%) and were considered significant in 17: 7 with supraventricular tachycardia, 7 with more than 6 ventricular premature systoles per minute, 2 with ventricular tachycardia and 1 with multifocal supraventricular premature systoles. These arrhythmias were observed when the dose of dobutamine was 20 micrograms/kg/min or more (p < 0.05). Hypotension developed in 11 patients (8%) and noncardiac effects in 13 (9%). The dobutamine test was interrupted for arrhythmias in 4% of cases, noncardiac side effects in 2% and poor image quality in 3%. A steady increment of heart rate 5 minutes after infusion of atropine was detected in 12 patients (maximal: 93 +/- 23 beats per minute; after five minutes: 94 +/- 19) and side effects were encountered in only one of these patients (hypotension). CONCLUSIONS: Intravenous administration of dobutamine during echocardiography can be finished in the majority of patients with good tolerance in spite of its side effects. Arrhythmias with dose over 20 micrograms/kg/min, poor image quality and chronotropic insufficiency are the most frequently encountered limitations.

Influence of mitral regurgitation on the response to captopril therapy for congestive heart failure caused by idiopathic dilated cardiomyopathy.

To assess the influence of mitral regurgitation (MR) on the response to captopril therapy for congestive heart failure (CHF), 30 patients with idiopathic dilated cardiomyopathy in New York Heart Association functional class III were studied. Left ventricular end-diastolic diameter and stroke volume were measured by Doppler echocardiography, and exercise tolerance by exercise testing before and at 1, 3 and 12 months after treatment. Patients were classified into 2 groups: those with (n = 14) and those without (n = 16) MR. No significant differences were observed between the 2 groups in pretreatment studies. Exercise tolerance increased significantly in the group with MR (p less than 0.001) during the year of follow-up, from 514 +/- 193 seconds at baseline study to 671 +/- 178 seconds (p less than 0.0005) at 1 month, 688 +/- 127 seconds (p less than 0.0005) at 3 months and 690 +/- 108 seconds (p less than 0.01) at 12 months. The group without MR had no significant changes. Stroke volume increased significantly only in the MR group during follow-up (p less than 0.01), changing from 43 +/- 9 ml at baseline study to 52 +/- 11 ml (p less than 0.01) at 1 and 49 +/- 11 ml (p less than 0.01) at 3 months. At 12 months the increase was not statistically significant. Left ventricular end-diastolic diameter decreased more in the group with than without MR, although the differences were not significant. Thus, the presence of dynamic MR appears to be an important factor in the therapeutic response to captopril therapy for CHF.

Echocardiographic findings in pannus ingrowth on an omniscience mitral prosthesis.

Serial echocardiographic findings in a patient with an Omniscience mitral prosthesis presenting progressive perivalvular pannus ingrowth are described. The first echocardiographic study was carried out one year after prosthesis implantation and showed decreased prosthetic opening velocity. As prosthetic thrombosis was suspected, hemodynamic study was performed, which proved normal. The patient remained in functional grade II for a year and a half prior to the onset of progressive dyspnea and dizzy spells. Echocardiogram was thus repeated and revealed the presence of multiple dense echoes behind the prosthetic disc. Three months after this last study, the patient presented acute pulmonary edema and reduction of disc excursion and opening and closing velocities. Hemodynamic study suggested prosthetic obstruction. Surgery revealed the presence of perivalvular pannus trapping the prosthetic disc. The prosthesis was subsequently replaced by a Björk-Sorin. This case emphasizes the usefulness of echocardiography in the early detection of perivalvular pannus ingrowth revealing prosthetic mobility anomalies, even before hemodynamic changes occur.