A case of repeated occlusion in the common iliac artery due to an unexpected stent deformation.

We report a case experiencing repeated common iliac artery (CIA) occlusion due to an unexpected stent deformation. A 74-year-old man with intermittent claudication had undergone balloon-expandable stenting for the left CIA. Six years after his first stent implantation, his left CIA was totally occluded inside the stent. We performed revascularization for the left CIA and achieved sufficient balloon inflation and balloon-expandable stenting. Then, one and a half years later, his left CIA was re-occluded. CT angiography showed compression by the protruding hyperostotic lumbar vertebral body, such that both stents had become deformed into a crescent shape. We were told that he had been using a powerful massage machine to stretch and relieve his spondylotic back pain. We suspected that the external pressure of the hyperostotic spondylosis and massage might have caused the CIA compression and repeated crush of the stents.

Efficacy of metal tip catheter for chronic total occlusion lesions in peripheral arterial disease.

We performed several techniques for chronic total occlusion (CTO) lesions in peripheral arterial disease (PAD). We evaluated the cases using the metal tip catheter (MT). We performed peripheral endovascular therapy (EVT) using MT in 31 cases 32 lesions of PAD from March 2007 to March 2011. Twenty-nine cases were CTO lesions using MT for back up of guidewire or MT alone in order to penetrate like a bougie with the blunt tip of MT. Two cases were acute arterial thrombosis for thrombectomy. Seven cases were CTO of the iliac artery (IA) and 25 cases were of the femoral artery (FA). Seven cases were in-stent restenosis. All 7 cases of IA were successfully treated with the initial techniques. We were unable to penetrate by MT(MT-) in 7 cases of FA, and in 2 cases out of the 7, we were even unable to cross the guidewire. Mean lesion length was 80 ± 42 mm in IA and 188 ± 88 mm in SFA. Among them, MT- was 164 ± 67 mm with no significant differences. Procedure time of EVT for CTO using MT was significantly shorter than other strategies. We had no complications such as perforation by using MT. MT provides high initial success rate by spectacular penetration performance and pushability. MT is a safe and effective device for CTO in PAD.

Central sympathetic inhibition augments sleep-related ultradian rhythm of parasympathetic tone in patients with chronic heart failure.

BACKGROUND: Abnormal sleep dynamics in patients with heart failure is one of the mechanisms for the relative predominance of central sympathetic outflow over parasympathetic tone. This study was designed to examine whether central sympathoinhibition could improve the sympathovagal imbalance related to rapid-eye-movement (REM)/non-REM ultradian sleep rhythm in these patients. METHODS AND RESULTS: Beat-by-beat RR intervals of overnight electrocardiogram were serially subject to power spectral analysis in 14 patients with chronic heart failure and 13 age-matched subjects with normal cardiac function. To assess autonomic sleep dynamics, the ultradian rhythm was extracted from all-night consecutive high-frequency (HF) components of heart rate variability (HRV) before and after administration of an (alpha2)-adrenergic agonist, guanfacine. Night-time HRV in heart failure was characterized by an attenuated ultradian rhythm of HF-components with a concomitant reduction in averaged HF power. Guanfacine reduced blood pressure, heart rate, and plasma norepinephrine concentrations by 7%, 8%, and 34% (p < 0.01), respectively. After guanfacine, HF power rose by 154% (p < 0.01) with a prominent augmentation of the all-night ultradian rhythm (+361%, p < 0.01). CONCLUSIONS: Central sympathoinhibition augments a sleep-related ultradian rhythm of parasympathetic tone, suggesting a potential benefit to autonomic balancing and sleep quality in patients with chronic heart failure.

Circadian dynamics of heart rate and physical activity in patients with heart failure.

The present study was designed to develop a method to continuously measure Holter electrocardiogram (ECG) and physical activity in terms of metabolic costs to examine circadian dynamics of RR intervals and physical activity in patients with heart failure. A total of 7 healthy subjects and 3 heart failure patients performed cardiopulmonary exercise test using four-stage graded treadmill walking at 0% grade to examine whether the acceleration signals in the vertical direction could reflect actual body energy expenditure during physical activity. Then, using this new method, 24-hr monitorings of ECG and physical activity were performed in 24 inpatients with heart failure while they were allowed to walk around freely. Our results showed the integral of rectified acceleration signals was closely correlated with actual metabolic cost in all subjects. Instantaneous changes in heart rate were quite concordant with physical activity. As compared with the asymptomatic patients (n = 12), the symptomatic patients (n = 12) had lower energy expenditure during 8-hr daytime periods but higher mean heart rate. Furthermore, a more prominent ultradian rhythm of circadian changes in heart rate and physical activity was found in 50% of all subjects studied. The simultaneous analysis of Holter ECG and physical activity as the same time series revealed that in patients with heart failure, sympathovagal balance shifted toward sympathotonic conditions and their physical activity could become subject to intrinsic ultradian dynamics of body's homeostasis.