Takashi Sueda

Relation between collateral flow assessed by Doppler guide wire and angiographic collateral grades

We investigated the relation between the angiographic collateral grade (Rentrops classification) and the collateral flow velocity pattern in 43 patients with angina pectoris. Collateral flow velocity was measured with a Doppler guide wire during balloon occlusion in coronary angioplasty. Collateral flow was detected in 21 of the 43 patients. In 6 of the 21 patients, collateral vessels were not seen angiographically before angioplasty. The direction of collateral flow was classified as forward, backward, or bidirectional. Forward and backward collateral flows were seen in all angiographic grades. Bidirectional collateral flows were observed only in grades 0 to 2. The peak collateral flow velocity was not correlated with the angiographic grades, but the ratio of the collateral flow duration to a cardiac cycle length was correlated with them (grade 0, 44% +/- 15%; grade 1, 70% +/- 16%; grade 2, 84% +/- 11%; and grade 3, 93% +/- 3%; p < 0.0005, analysis of variance). The peak velocity integral was also correlated with the angiographic collateral grades (p < 0.05; analysis of variance). The peak velocity integral was also correlated with the angiographic collateral grades (p < 0.05; analysis of variance). Electrocardiographic signs of ischemia were less observed in patients with unidirection and longer duration of collateral flow pattern (p < 0.05, respectively). A Doppler guide wire may be useful in assessing collateral flow grade.

Ergonovine-Induced Alterations in Coronary Flow Velocity Preceding Onset of Occlusive Spasm in Patients Without Significant Coronary Artery Stenoses

This study examined serial changes in coronary flow velocity to elucidate the dynamic change of coronary circulation during coronary spasm. Twenty patients with variant angina and 27 control patients were studied. Coronary flow velocity was monitored using a Doppler guidewire following intracoronary ergonovine administration. In the control group, diastolic flow velocity either did not change or increased slightly in response to ergonovine. However, in patients with variant angina, 2 patterns of flow velocity alterations were observed. In the first pattern, flow initially increased and then suddenly decreased (16 of 20 patients). In the second pattern, flow gradually decreased (3 of 20 patients). In the remaining patient, the coronary flow alteration could not be detected because of branch spasm. When abnormally high flow velocity was defined as a 100% increase in flow after ergonovine administration within 1 minute, and abnormally low flow velocity was defined as a 50% decrease in flow to diagnose variant angina, sensitivities of 35%, 75%, and 85% were noted if flow was measured 1.0, 2.0, and 3.0 minutes after ergonovine administration, respectively. These abnormal flow velocities were observed before ischemic ST changes appeared. In conclusion, in patients with variant angina, characteristic serial changes in coronary flow velocity occur before occlusive spasm. Variant angina may be diagnosed earlier by monitoring flow velocity rather than by monitoring for ischemic electrocardiographic changes.

Time interval determination from left atrial appendage ejection flow in patients with mitral stenosis.

The feasibility of determining the time interval from left atrial appendage (LAA) flow was examined using transesophageal Doppler echocardiography. Time intervals were compared between LAA flow and mitral flow patterns during late diastole in 8 patients with mitral stenosis and in 12 controls. The start of ejection flow from the LAA was later than the initiation of mitral flow, but the termination was same in both flows, indicating the contribution of LAA ejection to the latter half of the left atrial booster pump function. The pre‐ejection time and the time interval from P‐wave to end‐ejection correlated significantly with left atrial dimensions (r = 0.55, and r = 0.70, respectively). The pre‐ejection time, duration of the ejection flow from the LAA, and duration of mitral flow in the atrial contraction phase were significantly longer in patients with mitral stenosis (126 ± 14 msec, 131 ± 36 msec, and 167 ± 28 msec, respectively) than in the controls (109 ± 13 msec, 108 ± 15 msec, and 141 ± 17 msec, respectively). These results indicate that electrical conduction time from the right atrium to LAA can be estimated from the LAA ejection flow, and the time is related to the left atrial size. In patients with mitral stenosis, LAA contraction may contribute to left ventricular filling in the latter half of the atrial contraction phase.

Endovascular technique using a snare and suture for retrieving a migrated peripherally inserted central catheter in the left pulmonary artery

We report a successful endovascular technique using a snare with a suture for retrieving a migrated broken peripherally inserted central catheter (PICC) in a chemotherapy patient. A 62-year-old male received monthly chemotherapy through a central venous port implanted into his right subclavian area. The patient completed chemotherapy without complications 1 mo ago; however, he experienced pain in the right subclavian area during his last chemotherapy session. Computed tomography on that day showed migration of a broken PICC in his left pulmonary artery, for which the patient was admitted to our hospital. We attempted to retrieve the ectopic PICC through the right jugular vein using a gooseneck snare, but were unsuccessful because the catheter was lodged in the pulmonary artery wall. Therefore, a second attempt was made through the right femoral vein using a snare with triple loops, but we could not grasp the migrated PICC. Finally, a string was tied to the top of the snare, allowing us to curve the snare toward the pulmonary artery by pulling the string. Finally, the catheter body was grasped and retrieved. The endovascular suture technique is occasionally extremely useful and should be considered by interventional cardiologists for retrieving migrated catheters.

Guidewire Bias in Rotational Atherectomy in the Angled Lesion

The effect of guidewire bias on angled-lesion ablation by rotational atherectomy (RA) was assessed by measuring the changes in vertical lumen diameter, horizontal lumen diameter and the intima-media thickness of the coronary artery, using intravascular ultrasound in 10 lesions with an angle greater than 10 degrees. The vertical and horizontal diameters significantly increased after RA. The intima-media thickness at the 4 orthogonal sites significantly decreased. There was a significant positive correlation between vertical diameter change and angle (r=0.642, p=0.045), but none between horizontal diameter change and angle. There was no correlation between intima-media thickness change at 0 degrees and angle; however, at 180 degrees there was a tendency to correlation with angle (r=0.602, p=0.066). These data suggest that in cases of angled lesions, the increase in vertical lumen diameter is caused more by ablation of the 180 degrees wall than by that of the 0 degrees wall, which is brought about by guidewire bias toward the vascular wall at 180 degrees.

A New Proposal for Crossing Two or More Sheaths through Single Trans-Septal Puncture in Ablation of Atrial Fibrillation: Experience with Steerable Introducer

Introduction: We have sometimes experienced difficulty in crossing two or more sheath through one septal puncture for catheter based pulmonary vein isolation.

Highly mobile pedunculated left atrial appendage thrombus falling into the mitral valve orifice

We treated two patients with atrial fibrillation and stringlike left atrial appendage thrombus: a 66 year-old man who had apical hypertrophic cardiomyopathy and a 86 year-old woman with no underlying heart disease. In the patient with hypertrophic cardiomyopathy, transesophageal echocardiography showed a highly mobile stringlike echo protruding from the left atrial appendage and sometimes falling into the mitral orifice. Pathologic examination after excision proved the stringlike echo to be a pedunculated structure composed of red and white thrombi. Excision of thrombus was also planned for the woman, who had a history of recurrent cerebral embolism. Because her cerebral CT showed infarction with bleeding, however, surgery was postponed. The stringlike mobile thrombus was not detected by transesophageal echocardiography 1 month later, when a new embolic episode affected a foot. Clinical outcomes of these two patients differed remarkably. The critical findings by transesophageal echocardiography which facilitated differential diagnosis from cardiac tumors were: spontaneous contrast echo accompanying mural thrombuslike echo, and low flow velocity in the left atrial appendage. However, the differential diagnosis may be quite difficult in cases of tumors associated with atrial fibrillation.