Conduction gap mapping of linear ablation lesions with high-density mapping.

INTRODUCTION: When performing linear ablation, creating contiguous and transmural lesions are technically challenging due to the difficulty in finding electrical conduction gaps. We hypothesized that high-density mapping could identify the gaps. METHODS AND RESULTS: This study included consecutive patients who underwent conduction gap mapping of de novo lesions (41 patients, 55 lines) and previous lesions (25 patients, 34 lines). We analyzed the utility of bipolar and unipolar conduction gap mapping and retrospectively assessed the voltage and morphology of the bipolar electrograms at the gap sites. Bipolar and unipolar propagation maps were classified into three types: the propagation wavefront traveled through the linear ablation lesions (direct leak), the wavefront jumped to an opposite site across the line and returned to the line (jump and return leak), and others (indefinite leak). In the jump and return leak maps, the site where it returned suggested a conduction gap site. Bipolar propagation maps identified 30 (54.5%) conduction gaps and unipolar maps identified 40 (72.7%) gaps at de novo linear ablation lesions (P = .01), and 32 (94.1%) gaps and 33 (97.1%) gaps, respectively, at previous lesions (P = .56). Bipolar voltage mapping did not add any further efficacy in detecting conduction gaps, and the morphology of the electrograms recorded at the gap sites was not related to the types of propagation maps. CONCLUSION: Conduction gaps of linear ablation lesions can be visualized by high-density mapping with a high probability. Unipolar propagation, when used with bipolar mapping, may help detect conduction gap sites.

Successful catheter ablation in an octogenarian with persistent atrial fibrillation complicated by cor triatriatum sinister: a case report.

Background: Cor triatriatum sinister (CTS) is a rare congenital heart defect sometimes complicated with atrial fibrillation (AF). Catheter ablation (CA) relieves the AF-associated symptoms, but CA for AF with CTS has been reported rarely. Because CTS can be associated with other congenital heart disease, detailed preoperative assessment is important. Case summary: An 80-year-old man was referred to our institution for shortness of breath that had persisted for 2 months when he was first diagnosed with AF. Transthoracic echocardiography revealed an enlarged left atrium (LA) divided into two chambers by a membrane. Transoesophageal echocardiography showed the membrane extending from the fossa ovalis (FO) to the Coumadin ridge, with the accessory (dorsal) chamber (AC) in closer proximity to the FO. Computed tomography showed that all pulmonary veins (PVs) flowed into the AC, with no PV anomalies. No other heart anomaly was identified, with no thrombus in the LA. With these findings, PV isolation (PVI) with CA was considered safe. Transseptal puncture was performed with intracardiac echocardiography for precise catheterization of the AC. Pulmonary vein isolation was performed successfully. The patient was discharged 4 days after the procedure, without any complications. His symptoms improved post-procedure, and sinus rhythm was maintained without antiarrhythmic drug therapy during the 18-month follow-up. Discussion: Cor triatriatum sinister is a rare anomaly that accounts for 0.1% of all congenital heart diseases. Cor triatriatum sinister sometimes complicated with symptomatic AF. Detailed preoperative anatomical assessment with multiple imaging modalities helped us achieve safe and effective CA for a patient with AF and CTS, even in an octogenarian.

Aortic Mural Thrombus Associated with Congenital Protein C Deficiency in an Elderly Patient.

Thrombophilia increases the risk of venous thrombosis, but is rarely responsible for aortic thrombosis. Aortic mural thrombus (AMT) may be associated with a protein C deficiency. However, it is necessary to determine whether the protein C deficiency is congenital/hereditary or secondary/acquired (consumption of protein C during the process of thrombus formation). This study describes a 77-year-old Japanese woman with incidentally diagnosed AMT, who had a protein C deficiency (activity 54%, antigen 42%). Sequencing of the protein C gene revealed a heterozygous mutation of c.1268delG, p.Gly423Valfs＊82 in exon 9, indicating a congenital protein C deficiency. These findings indicate that very late onset AMT can occur in an adult with congenital protein C deficiency.

A Case of Acute Myocardial Infarction due to Left Main Trunk Occlusion Complicated With Aortic Dissection as Diagnosed by Intravascular Ultrasound.

A 52-year-old man was transferred to our hospital with a sudden onset of severe chest pains. His electrocardiogram revealed ST-segment elevation suggestive of acute myocardial infarction. Emergency coronary angiography showed subtotal occlusion of left main trunk (LMT) with delayed coronary flow. Because intravascular ultrasound revealed a large intimal flap, we diagnosed aortic dissection involving the LMT. After stenting of the LMT, the patient underwent surgical repair of the aortic dissection. Although it is difficult to obtain a correct diagnosis of aortic dissection complicated with myocardial ischemia, we succeeded in diagnosing this rare condition by use of a intravascular ultrasound.