Leinveber, Pavel

Background: Obstructive sleep apnea (OSA) imposes an afterload burden on the left ventricle and increases the pressure gradient across the intrathoracic aorta. This might increase the likelihood of aortic dissection (AD). We hypothesized that patients with acute AD would have a high prevalence of previously undiagnosed OSA and a largely nocturnal presentation. Methods: 40 consecutive, consenting subjects with acute AD who survived to hospital discharge were collected from 4 institutions. Mean age was 57 (range 28-75), 24 were male. 25 had type A dissection and 15 type B. 37 completed the modified Berlin Questionnaire and 30 had attended overnight polysomnography. Presenting CT scans had aortic diameter measured at a) the sinotubular junction b) ascending aorta c) origin of innominate d) mid-arch e) origin of left subclavian f) mid-descending aorta g) level of diaphragm; CT scans at 3 months were available in 24 subjects. Results: AHI ranged from 0 - 89; prevalence of OSA (defined by apnea-hypopnea index [AHI] > 5) was 63%. There were no differences in aortic diameter at any level comparing OSA vs non-OSA, regardless of AHI cutoff (>5, >15, >30; figure). Over time aortic diameter decreased at the level of the sinotubular junction and ascending aorta (expected - due to surgery). Whether dissection occurred during overnight hours (10 PM - 7 AM) did not differ by presence/absence of OSA (regardless of AHI cutoff). In those with high-risk Berlin questionnaires (>=2 categories positive) 10/21 (48%) dissections occurred during sleeping hours vs 2/13 (15%) in low risk Berlin group (p = 0.08, Fisher’s exact test). Conclusions: Among patients with acute AD the prevalence of OSA was high. Aortic diameters, however, were not different according to level of AHI. Presence of OSA defined by polysomnography was not associated with a nocturnal presentation in this sample.

AbstractBackgroundObstructive sleep apnea (OSA) imposes an afterload burden on the left ventricle and increases the pressure gradient across the aortic wall. Thus, OSA may increase the risk for aortic dissection (AD).MethodsThis study enrolled 40 subjects with acute AD from four institutions; 37 completed the modified Berlin Questionnaire and 31 underwent attended overnight polysomnography. Aortic diameter was measured on a computed tomography scan at seven locations from the sinotubular junction to the diaphragm.ResultsTwenty‐seven subjects had type A dissection; 13 had type B. In those who had polysomnography apnea–hypopnea index (AHI) ranged from 0.7 to 89. Prevalence of OSA (AHI ≥ 5) was 61%. Nocturnal presentation (10 p.m.–7 a.m.) did not differ by presence/absence of OSA. The modified Berlin Questionnaire was not predictive of the presence of OSA. Among type A subjects with polysomnography (n = 23), aortic diameters at all locations were greater in the OSA group though differences were not statistically significant. Summating aortic diameters at the seven locations also yielded a numerically larger mean value in the OSA group versus the non‐OSA group.ConclusionsIn this sample of patients with acute dissection, OSA was prevalent but was not associated with a nocturnal presentation. The presence of underlying OSA may be associated with larger aortic diameters at the time of dissection compared to patients without OSA. Though differences did not meet statistical significance the current series is limited by small numbers.

Background— Obstructive sleep apnea is highly prevalent in patients with cardiovascular disease and has detrimental effects on systolic and diastolic function of the ventricles. In this research, the changes in strain (S) and strain rate (SR) during the performance of the Mueller maneuver (MM) in an effort to better understand how negative intrathoracic pressures affect ventricular mechanics. Methods and Results— The MM was performed to maintain a target intrathoracic pressure of −40 mm Hg. Echocardiography was used to measure various parameters of cardiac structure and function. Myocardial deformation measurements were performed using tissue speckle tracking. Twenty-four healthy subjects (9 women; mean age, 30�6 years) were studied. Global left ventricular longitudinal S in systole and SR in early filling were significantly decreased during the MM (S: baseline, −17.0�1.6%; MM, −14.5�2.2%; P <0.0001, SR: baseline, 1.09�0.20 s −1 ; MM, 0.92�0.21 s −1 ; P =0.01). Global right ventricular longitudinal S was also significantly decreased during the MM (baseline, −22.0�3.1%; MM, −17.2�2.5%; P <0.0001), as was global right ventricular longitudinal systolic SR (baseline, −1.34�0.35 s −1 ; MM, −1.02�0.21 s −1 ; P =0.0006). Conclusions— Left ventricular and right ventricular longitudinal deformation are significantly reduced during the MM. These results suggest that negative intrathoracic pressure during apnea may contribute to changes in myocardial mechanics. These results could help explain the observed changes in left ventricular and right ventricular mechanics in patients with obstructive sleep apnea.