Shiro Yamachika

Preserving Normal Ventricular Activation Versus Atrioventricular Delay Optimization During Pacing: The Role of Intrinsic Atrioventricular Conduction and Pacing Rate

The purpose of the study was to compare the effects of DDD pacing with optimal AV delay and AAI pacing on the systolic and diastolic performance at rest in patients with prolonged intrinsic AV conduction (first‐degree AV block). We studied 17 patients (8 men, aged 69 ± 9 years) with dual chamber pacemakers implanted for sick sinus syndrome in 15 patients and paroxysmal high degree AV block in 2 patients. Aortic flow and mitral flow were evaluated using Doppler echocardiography. Study protocol included the determination of the optimal A V delay in the DDD mode and comparison between AAI and DDD with optimal A V delay for pacing rate 70/min and 90/min. Stimulus‐R interval during AAI (AHI) was 282 ± 68 ms for rate 70/min and 330 ± 98 ms for rate 90/min (P < 0.01). The optimal A V delay was 159 ± 22 ms, A V delay optimization resulted in an increase of an aortic flow time velocity integral (AFTVI) of 16%± 9%. At rate 70/min the patients with ARI ≤ 270 ms had higher AFTVI in AAI than in DDD (0.214 ± 0.05 m vs 0.196 ± 0.05 m, P < 0.01), while the patients with ARI > 270 ms demonstrated greater AFTVI under DDD compared to AAI(0.192 ± 0.03 m vs 0.166 ± 0.02 m, P < 0.01). At rate 90/min AFTVI was higher during DDD than AAI (0.183 ± 0.03 m vs 0.162 ± 0.03 m, P < 0.01). Mitral flow time velocity integral (MFTVI) at rate 70/min was higher in DDD than in AAI (0.189 ± 0.05 m vs 0.173 ± 0.05 mP < 0.01), while at rate 90/min the difference was not significant in favor of DDD (0.149 ± 0.05 m vs 0.158 ± 0.04 m). The results suggest that in patients with first‐degree AV block the relative impact of DDD and AAI pacing modes on the systolic performance depends on the intrinsic AV conduction time and on pacing rate.

Thrombus removal with a temporary vena caval filter in patients with acute proximal deep vein thrombosis.

Between September 1999 and January 2001 we performed thrombus removal with the use of a temporary vena caval filter in 11 patients who had acute iliofemoral venous thrombosis. To facilitate thrombus removal, 5 patients initially received catheter-directed thrombolytic therapy (thrombolysis group), and the other 6 received surgical thrombectomy (thrombectomy group). Residual thrombus was confirmed after initial catheter-directed thrombolysis in all patients in the thrombolysis group, and thrombolysis was continued in the ward. Bleeding complications subsequently occurred in 2 patients. In the thrombectomy group, 1 patient had residual thrombus just below the temporary filter, and a permanent vena caval filter was deployed for removal. Another patient had a residual thrombus in the superficial femoral vein, and rethrombectomy was performed. One patient in the thrombectomy group died of pneumonia. All other patients were discharged. There were no deaths from pulmonary thromboembolism in this series. Post-thrombotic syndrome occurred in 2 of the 5 patients in the thrombolysis group (40%) and in 3 of the 6 patients (50%) in the thrombectomy group. We conclude that a temporary vena caval filter is useful for the management of acute proximal deep vein thrombosis, especially when aggressive treatment is required.

Beneficial Effects of Angiotensin-Converting Enzyme Inhibitor on Renal Function and Glucose Homeostasis in Diabetics with Hypertension

The antihypertensive efficacy of enalapril and its effects on renal function and glucose homeostasis were investigated in 9 hypertensive patients with non-insulin-dependent diabetes mellitus. Enalapril therapy produced a significant fall in blood pressure (BP) (p less than 0.05) and a significant increase in renal blood flow (p less than 0.05) without a change in glomerular filtration rate. Furthermore, fasting plasma glucose was significantly reduced (p less than 0.01). Similarly, M value, as an index of plasma glucose control in diabetes, was significantly reduced from 19.6 to 10.1 (p less than 0.01). These findings suggested that the angiotensin-converting enzyme inhibitor enalapril was effective in reducing BP and improving renal function, and might improve glucose homeostasis in hypertensive diabetics.

Three cases of ischemic ulcer due to arteriosclerosis obliterans responding to basic fibroblast growth factor spray.

The management of the chronically ischemic leg with ulcer formation that is not suitable for either surgical or interventional treatment is still a matter of controversy. We describe three cases of ischemic ulcer treated with basic fibroblast growth factor spray. Ulcer healing was accelerated and complete epithelialization was achieved in all cases. Basic fibroblast growth factor spray is useful in the treatment of the ischemic ulcer in patients with arteriosclerosis obliterans, especially in high-risk surgical patients.

Consideration of prosthesis-patient mismatch and left ventricular mass regression after implantation of the Carpentier-Edwards pericardial valve in elderly Japanese patients: body surface area may be irrelevant.

The assessment of prosthesis patient mismatch (PPM) for small aortic annulus is important for prognosis after aortic valve replacement (AVR). Recent investigations have demonstrated that PPM occurs in AVR patients with an indexed effective orifice area (iEOA) of less than 0.85u2009cm2/m2. We investigated hemodynamic performance and left ventricular mass (LVM) regression after AVR. Eighteen patients who underwent AVR using a 19-mm Carpentier-Edwards pericardial (CEP) valve without annular enlargement were studied by echocardiography and Doppler examination 4 months after AVR. Patients were divided into two groups on the basis of their body surface area (BSA); the smaller BSA (group S, 1.14–1.36u2009m2, nine patients) and the larger BSA (group L, 1.40–1.83u2009m2, nine patients). Of these 18 patients, ten underwent isolated AVR, and five underwent AVR with coronary artery bypass graft; (i.e., double valvular replacement, AVR with maze procedure, and AVR with mitral valvulophasty. There were no statistically significant differences between the two groups, except for age (group S, 78.3 ± 2.5 years; group L, 73.6 ± 2.4 years). There was no significant difference for the iEOA during the late phase at rest (group S, 1.10 ± 0.26 cm2; group L, 1.02 ± 0.28u2009cm2). However, there was a significant difference for the LVM regression between the preoperative and postoperative values (group S, 243 ± 23.6u2009mg/cm2 [pre], 190 ± 16.9u2009mg/cm2 [post]; group L, 302 ± 13.7u2009mg/cm2 [pre], 199 ± 16.7u2009mg/cm2 [post]). In elderly Japanese patients with a BSA of less than 18u2009m2, we demonstrated LVM regression and avoidance of PPM after implantation of the aortic 19-mm CEP valve.

Demonstration and Operative Influence of Low Prime Volume Closed Pump

Various improvements have been made in cardiopulmonary bypass (CPB) in the past few decades. We designed a new type of CPB to reduce the secretion of systemic inflammatory markers. We used a low prime volume pump (LPVP), completely closed CPB circuit and examined coagulant factors and inflammatory cytokines. In this study, we demonstrate the efficacy of LPVP using molecular biological data. Fourteen patients were randomized prospectively into two groups: Group L patients underwent LPVP (n = 8) and Group N patients underwent normal prime volume CPB (n = 6). We measured thrombin-antithrombin III complex (TAT), complement factor (C3a), and interleukin (IL)-10 levels at four time points. TAT (66.1 ± 15.1 ng·mL−1), C3a (1895 ± 282 ng·mL−1) and IL-10 (486 ± 114 pg·mL−1) levels in Group N were significantly higher than in Group L (TAT, 19.5 ± 4.4 ng·mL−1; IL-10, 105 ± 24.6 pg·mL−1; C3a, 1349 ± 369 ng·mL−1) immediately following CPB. LPVP demonstrated a lower systemic inflammatory response compared to normal prime volume CPB, as assessed using a molecular biological approach.

A rare case of aortic tube graft occlusion 35 years after coarctectomy

A 52-year-old male with a history of repair of aortic coarctation by prosthetic tube graft replacement 35-years ago developed anterior spinal artery syndrome caused by acute functional occlusion of the aorta at the repair site where pseudoaneurysm formation was observed. The patient was rescued by an emergency axillofemoral bypass, and residual hypertension in upper limbs was improved by elective ascending aorta-descending aorta bypass grafting.

Mechanical Tricuspid Valve Thrombosis with Intermittent Posterior Movement of Intraventricular Septum

A 56-year-old woman was urgently admitted following an episode of syncope. Fourteen years earlier, she had undergone implantation of a tricuspid prosthesis due to Ebstein anomaly, with congestive heart failure (NYHA class III) and severe tricuspid regurgitation. A mechanical prosthesis had been selected (31-mm Medtronic-Hall® valve; Medtronic Inc., Minneapolis, Minnesota, USA) because of its structural tolerance and the relatively young age of the patient. Since that time she had been taking warfarin daily to maintain the international normalized ratio between 2.5 and 3.5. Transthoracic echocardiography showed intermittent posterior movements of the interventricular septum during diastole (Figure, A). Cineradiography confirmed an intermittent opening movement of the tilting disc, despite the fact that the opening angle was patent (Figure, B). We were concerned that the intermittent posterior movement of the interventricular septum might be caused by intermittent entry flow due to poor functioning of the mechanical valve. IMAGE IN CARDIOLOGY