Predictor of underlying myocardial damage in normally functioning left ventricle with narrow QRS complex: relationship between QRS duration at right ventricle pacing and iodine-123 metaiodobenzylguanidine myocardial scintigraphy.

OBJECTIVE: Washout rate of iodine-123 metaiodobenzylguanidine (MIBG) myocardial scintigraphy is correlated with the degree of myocardial damage. The aim of this study is to ascertain whether there is any relationship between QRS complex duration at right ventricle (RV) pacing and the degree of myocardial damage assessed by I-123 MIBG myocardial scintigraphy in normally functioning left ventricle. METHODS: The study included 22 patients (10 men and 12 women, ranging in age from 48 to 89 years), with atrioventricular (AV) block (n = 15) and sick sinus syndrome (n = 7). All patients had baseline QRS duration of less than 120 ms and received implantation of a DDD-mode permanent pacemaker. Iodine-123 MIBG myocardial scintigraphy was performed before the pacemaker implantation, and QRS duration at RV pacing at a rate of 70 ppm was calculated immediately after the implantation. RESULTS: With the use of RV pacing, QRS duration was prolonged ranging from 122.4 to 185.6 ms with a mean of 153.2 +/- 15.2 ms. Washout rate of I-123 MIBG myocardial scintigraphy (WR) was calculated as ranging from 5.0 to 83.0% with a mean of 44.2 +/- 17.5%. There was a strong correlation between WR and QRS duration at RV pacing (r = 0.735, p < 0.001). CONCLUSIONS: It was confirmed that WR of I-123 MIBG was correlated positively with QRS duration at RV pacing. Measurement of QRS duration may be helpful to evaluate the degree of underlying myocardial damage even in the normally functioning left ventricle.

Progressive congestive heart failure due to common iliac arteriovenous fistula: a case report.

Arteriovenous shunt is one of the causes of heart failure, but heart failure caused by common iliac arteriovenous fistula is relatively rare. A 64-year-old man who developed acute heart failure due to venous perforation of a common iliac aneurysm and also had bilateral aneurysms (diameter 58 mm) was referred to our department. On admission, the patient complained of dyspnea and swollen left leg, so diuretic agent was administered to treat the heart failure. Cardiac catheterization showed a shunt rate of 80.6%, as well as 5.0 Qp/Qs and O2 step-up across perforation of the common iliac vein. Despite the therapy, pleural effusion and ascites exacerbated, and the heart failure became difficult to control, so surgical treatment was performed. The aneurysm was replaced with an artificial vessel, and the fistula was closed by direct suturing. Postoperatively, the symptoms disappeared, and the patient is in good health.

Discrepancy between Doppler and catheter measurements of pressure gradients across small-size prosthetic valve.

OBJECTIVES: The exact role of pressure gradient across the prosthetic valve estimated from Doppler flow velocity remains controversial. This in-vivo study was designed to assess the actual discrepancy between Doppler and catheter measurements of the pressure gradients for small bileaflet prosthetic valves in the aortic position. METHODS: Bileaflet prosthetic valves (19 mm-ATS) were implanted into the aortic position in pigs, and pressure gradients across the valves were examined by volume loading under right heart bypass. The pressure gradient obtained by catheter was defined as the conventional peak-to-peak gradient between the left ventricle and aorta. The peak Doppler gradients were calculated from the maximal instantaneous Doppler velocity with the ultrasound probe positioned on the diaphragm at the level of the cardiac apex. RESULTS: There were strong correlations between pressure gradients and cardiac output. The Doppler gradient was constantly higher than the catheter values, and the resultant discrepancy between Doppler and catheter measurements was directly dependent on cardiac output (y=9.9x+0.6, r2=0.55). For cardiac output > or = 5.0 L/min, the difference between Doppler and catheter gradients reached 40 mmHg, and maximum differences of up to 80 mmHg were observed. CONCLUSIONS: In view of the presence of striking overestimation of catheter gradient by Doppler measurement, Doppler ultrasound should be used cautiously to assess small-size bileaflet prosthetic valve function with consideration of the patient's hemodynamic state.

C-reactive protein and atrial fibrillation. Is inflammation a consequence or a cause of atrial fibrillation?

To clarify whether inflammation is a cause or consequence of atrial fibrillation (AF), we measured high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) before and after pharmacological cardioversion in 15 patients with paroxysmal AF. Levels of hs-CRP, IL-6, and TNF-alpha after cardioversion were significantly higher than those in controls (P < 0.05). Furthermore, the levels of these indices did not differ significantly even at 24 hours and 2 weeks after cardioversion. These results suggest that inflammation is a causative agent of paroxymal AF.