[Diagnostic value and safety of stress echocardiography protocol based on rapid pacing in patients with implanted pacemakers]. / Wartoscc diagnostyczna i bezpieczenstwo echokardiografii obciazeniowej z szybkim protokolem stymulacji serca u chorych z wszczepionym stymulatorem.

AIM OF THE STUDY: Assessment of safety and diagnostic value of stress echocardiography protocol based on rapid pacing in patients with implanted permanent pacemakers operating in AAI/DDD and VVI modes. MATERIAL AND METHODS: 88 rapid pacing stress echo tests were performed in 60 patients (39M, 21F, aged 47-79, mean 64 +/- 9 years), utilizing permanent pacemakers. Left ventricular segmental contractility was assessed at rest and during 100/min and 85% of predicted maximal heart rate. Each pacing stage lasted for 3minutes. The test was performed with the use of AAI/DDD or VVI pacing mode and then repeated with WV mode in pts with DDD pacemaker. Coronary stenosis of at least 50% was considered significant. Mean duration of the test was 9.9 +/- 1.7 min, including 6.7 +/- 1.4 min of pacing. RESULTS: No severe adverse effects were observed. Among 88 tests performed, AAI/DDD modes were used in 41 and VVI mode in 47 were as significant increase of the heart rate comparing to baseline was achieved - 68 vs 129/min; p<0.0001, including patients treated with beta-blockers - 69 vs 128/min; p < 0.0001. No significant differences in systolic blood pressure were found between rest and stress (126 vs 126 mm Hg). In 58 patients (66%) the test was considered positive for ischemia, in 29 (33%), negative and in 1 (1%) nondiagnostic. Sensitivity, specificity, accuracy, positive and negative predictive values were respectively: 92%, 66%, 79%, 78% i 86%. For AAI/ DDD modes the above values calculated for the entire group were: 95%, 75%, 85%, 79%, 94%, while for VVI mode they were: 90%, 56%, 73%, 76%, 77% (NS). In the presence of left ventricular hypertrophy the accuracy was 79% for AAI/DDD and 71% for VVI mode, and in patients without hypertrophy 92% and 74% respectively. CONCLUSIONS: A stress echo protocol using permanent pacemaker for rapid pacing is a brief and safe diagnostic technique. Accuracy of the test is similar regardless of the pacing mode used. The test can be utilized as a technique of choice for noninvasive diagnostics of coronary disease in patients with permanent pacemakers.

[Diagnostic and prognostic value of stress echo-pacing in patients with implanted AAI pace-maker]. / Wartosc diagnostyczna i prognostyczna echokardiografii obciqzeniowej z zastosowaniem stymulacji AAI ze stymulatora serca.

UNLABELLED: The aim of this study was to assess the utility, safety and prognostic value of echocardiographic stress test (EST) in non-invasive diagnosis of ischemic heart disease in patients (pts) with implanted pacemaker, with and without left ventricle hypertrophy. MATERIAL AND METHODS: EST was performed in 40 patients (mean age 60+/-10 years, from 43 to 78) with pacemaker. Using external programming system heart rate was accelerated by 10 beats in every 3 minute till reaching maximal heart rate. The examination was conducted only in patients with physiological stimulation of right atrium by AAI mode. Angiographically significant coronary artery stenosis size was accepted as over 50% artery diameter. Mean duration time of performed examination was 13+/-4 min. RESULTS: No adverse events were observed. The quality of stress echo visualization was good in every case. Heart rate at rest and at maximal stimulation were respectively 68+/-8 and 132+/-13 per minute (p<0.0001) and systolic blood pressure pressure 140+/-13 and 142+/-13 mmHg (ns). In 10 (25%) pts the result was positive, in 24 (60%) negative, and in 6 (15%) - non-diagnostic. Non-diagnostic result of the test was due to pacemaker limitation (1 pts), and achieving Wenckebach point (5 pts). Test specificity was 95%, sensitivity 69%, accuracy - 85%. Significant occlusion in coronary angiography were observed in 40% pts (including 1-vessel disease - 12,5%). In left ventricle hypertrophy group (n=19), the EST accuracy was 87% (without significant difference with non-hypertrophy group). In the group with beta blockers therapy (n=16) the observed accuracy was 93%. The follow-up time was 963+/-497 days. The prognostic value of positive EST result for cardiac events was 80%, and for negative - 100%. None of the pts with negative stress echo result suffered any cardiac event. CONCLUSIONS: EST is a safe, short lasting examination with good quality of echo visualization. This method seems to be of important value in diagnosing the ischaemic heart disease in pts with pacemaker, also with left ventricle hypertrophy and obligatory beta blockers medication.