Idiopathic left ventricular tachycardia following atrioventricular conduction block by rapid atrial tachycardia.

The present case demonstrated a rare situation alternating between a repetitive atrial tachycardia (AT) and ventricular tachycardia (VT). A unique induction mechanism was noted in which the VT was induced after Wenckebach AV node conduction block following the repetitive rapid AT.

Relevance of transthoracic left atrial appendage wall velocity measurement in addition to left atrial volume for noninvasive and quantitative assessment of left atrial thrombogenesis in patients with atrial fibrillation and normal D-dimer levels.

PURPOSE: This study examined the role of left atrial (LA) appendage wall velocity (LAAWV) measurement in addition to LA size for the noninvasive assessment of thrombogenesis in patients with atrial fibrillation (AF) and normal plasma D-dimer levels. METHODS: In 58 non-valvular AF patients, LAAWV and the LA volume index (LAVI) were determined by transthoracic echocardiography. LA appendage flow velocity and severity of spontaneous echo contrast (SEC) were determined by transesophageal echocardiography. RESULTS: LAAWV was strongly correlated with LA appendage flow velocity (r = 0.82), and LAVI was weakly correlated with LA appendage flow velocity (r = -0.37). As SEC severity increased, LAAWV decreased (p < 0.001) and LAVI increased (p < 0.001). Among 52 patients with normal D-dimer levels, LAAWV < 10 cm/s had 71 % sensitivity and 94 % specificity for diagnosing severe SEC. Severe SEC was not found in 18/32 large LAVI patients (>34 mL/m(2)), but 17 of the 18 patients (94 %) had LAAWV < 10 cm/s. Severe SEC was found in 3/20 patients with normal LAVI, but all of them showed LAAWV < 10 cm/s. CONCLUSION: The noninvasive measurement of transthoracic LAAWV in addition to LA volume is clinically relevant for quantitatively assessing thrombogenesis in AF patients with normal D-dimer levels.

High plasma human atrial natriuretic peptide and reduced transthoracic left atrial appendage wall-motion velocity are noninvasive surrogate markers for assessing thrombogenesis in patients with paroxysmal atrial fibrillation.

BACKGROUND: The clinical relevance of examining human atrial natriuretic peptide (HANP) or left atrial appendage (LAA) wall-motion velocity during sinus rhythm in paroxysmal atrial fibrillation (AF) patients has not been clearly elucidated. METHODS: The subjects were 38 patients with paroxysmal AF who underwent transesophageal and transthoracic echocardiography during sinus rhythm. The presence of spontaneous echocontrast (SEC) was examined with transesophageal echocardiography and LAA wall-motion velocity (LAAWV) was measured with transthoracic tissue Doppler echocardiography. Plasma HANP was measured within 3 hours after echocardiography. RESULTS: Human atrial natriuretic peptide ranged from 12 to 106 pg/mL with an average of 43 ± 24 pg/mL and had a significant correlation with LAAWV (r = -0.57) or LAA flow velocity (r = -0.41). HANP was significantly higher in patients with SEC than in patients without SEC (64 ± 29 vs. 34 ± 15 pg/mL, P = 0.008) and LAAWV was significantly lower in patients with SEC than in patients without SEC (13 ± 5 vs. 20 ± 5 cm/sec, P = 0.002). HANP >44 pg/mL had a sensitivity of 73% and specificity of 89% for diagnosing SEC. SEC was more frequently observed (73%) in patients with HANP >44 pg/mL and/or LAAWV <10 cm/sec as compared with patients (11%) with normal HANP and LAA wall-motion velocity (P < 0.0001). CONCLUSION: Higher plasma HANP and lower LAA wall-motion velocity may be noninvasive surrogate markers for assessing left atrial thrombogenesis during sinus rhythm in paroxysmal AF patients.

Efficacy of pulmonary vein isolation on left atrial function in paroxysmal and persistent atrial fibrillation and the dependency on its baseline function.

BACKGROUND: The effects of pulmonary vein (PV) isolation in atrial fibrillation (AF) on left atrial (LA) function or PV flow have not been well documented. METHODS: We examined the LA function and PV flow before and 3-6 months after PV isolation in 67 AF patients (34 paroxysmal [PAF] and 33 persistent [CAF]) using transesophageal echocardiography. RESULTS: AF recurred in 6/34 patients with PAF and in 6/33 patients with CAF 6 months after PV isolation. A larger LA dimension, a lower systolic PV flow velocity, and a lower ratio of systolic to diastolic PV flow velocity were related to a higher incidence of AF recurrence. The increment of left atrial appendage (LAA) flow velocity (55% vs. 22%) and systolic PV flow velocity (57% vs. 20%) after PV isolation tended to be greater in CAF than in PAF. The changes in LAA flow velocity had reverse correlations with the baseline values before PV isolation (PAF: r = -0.73, CAF: r = -0.58). The changes in mitral flow velocity during atrial contraction in PAF had reverse correlations with the baseline values before PV isolation (r = -0.84). The changes in systolic and diastolic PV flow velocity of PAF had reverse correlations with the baseline values before PV isolation (r = -0.56, r = -0.66). CONCLUSION: The baseline LA function may affect AF recurrence as well as the improvement of LA function, and the benefit of successful PV isolation might be greater in CAF than in PAF.

An extremely large coronary aneurysm associated with a quadricuspid aortic valve in an adult patient.

A 68-year-old woman exhibited an increasingly protruding mass on the left heart border on chest X-ray. Transthoracic echocardiography revealed an echo-free mass in the anterior pericardial space. Transesophageal echocardiography revealed blood flow from the proximal left anterior descending coronary into a large coronary artery aneurysm measuring 61 mm × 51 mm in diameter and a quadricuspid aortic valve with a small cusp between the left and right coronary cusps. Coronary angiography demonstrated the presence of a coronary aneurysm connected to the proximal left coronary anterior descending artery. A giant coronary artery aneurysm and pulmonary artery fistulas extending from the left and right coronary arteries were confirmed by surgeons and successfully treated with surgery.

Role of transthoracic left atrial appendage wall motion velocity in patients with persistent atrial fibrillation and a low CHADS2 score.

BACKGROUND AND PURPOSE: Thromboembolic risk has been examined by semi-invasive transesophageal echocardiography. We assessed the risk of thrombogenesis in patients with persistent atrial fibrillation (AF) noninvasively by using transthoracic tissue Doppler echocardiography (TDE) in relation to a low CHADS2 score. METHODS: Eighty patients with persistent AF underwent both transthoracic and transesophageal echocardiography. Peak left atrial appendage (LAA), wall motion velocity (WV) during LAA contraction was measured by transthoracic and transesophageal TDE. LAA flow velocity was also determined by transesophageal echocardiography. RESULTS: Transthoracic LAAWV could be measured in 78 of the 80 patients, and the values were closely correlated with transesophageal TDE values (r=0.98) and with transesophageal LAA flow velocity (r=0.82). Transthoracic LAAWV was significantly lower with increasing spontaneous echo contrast (SEC) severity (severe SEC, mild SEC, no SEC: 5.7±2.4, 10.2±3.3, and 14.5±5.5cm/s, respectively). Severe SEC was noted in 31 of 61 patients with a CHADS2 score ≤2, in 19 of 46 patients with a CHADS2 score ≤1 and in 6 of 21 patients with a CHADS2 score=0. For diagnosing severe SEC, a transthoracic LAAWV <10cm/s had a sensitivity of 81% and specificity of 92% in the patients with a CHADS2 score ≤2, a sensitivity of 74% and specificity of 91% in the patients with a CHADS2 score ≤1 and a sensitivity of 44% and specificity of 83% in the patients with a CHADS2 score=0. CONCLUSIONS: A transthoracic LAAWV <10cm/s in persistent AF patients with a low CHADS2 score may be a very specific diagnostic tool for evaluating severe SEC, one of the high risk factors for thromboembolism.

Differences of BiAtrial Substrate Properties in Patients with Different Types of AF.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in clinical practice and induces cardiac dysfunction and strokes. The development of AF requires a"trigger" and also an electroanatomic "substrate" capable of both initiating and perpetuating AF. Over the past decade, the understanding of the AF substrate properties in both atria has increased with fractionation and frequency analyses of the local atrial electrograms using three-dimensional electroanatomic mapping systems. The purpose of this review was to discuss the differences in the atrial substrate properties in patients with different types of AF.

Clinical usefulness of drug-eluting stents in the treatment of dialysis patients with coronary artery disease.

AIMS: To investigate the clinical outcomes of paclitaxel-eluting stents (PES) and sirolimus-eluting stents (SES) in patients on dialysis. METHODS AND RESULTS: Between May 2004 and December 2008, 95 patients on dialysis with 124 lesions were treated with PES alone, and were compared to 184 patients on dialysis with 244 lesions treated with SES alone, retrospectively. One-year major adverse cardiac event (MACE) including stent thrombosis, target lesion revascularisation (TLR), myocardial infarction (MI) and cardiac death were compared. Baseline characteristics were similar except for previous CABG (p = 0.02) and reference vessel diameter (p = 0.04). During hospitalisation, all cause death was more frequently observed in the PES group (p = 0.004). In-hospital MACE was not significantly different (p = 0.8). The incidence of 1-year MACE in the PES group was lower than that in the SES group (14.7%, 28.3%, p = 0.04), mainly due to the reduction of TLR (11.6%, 25.0%, p = 0.03). Rates of stent thrombosis (0%, 2.7%, p = 0.1), MI (1.1%, 3.8%, p = 0.2), and cardiac death (3.2%, 4.4%, p = 0.6) were not significantly different. CONCLUSIONS: PES appears to be more efficient in reducing angiographic and clinical restenosis in dialysis patients compared with SES.

A case of acute coronary syndrome caused by extrinsic compression of the left main coronary artery due to pulmonary hypertension.

Stenosis of the left main coronary artery (LMCA) due to extrinsic compression, producing symptoms of myocardial ischemia, is called left main compression syndrome. We report on a 43-year-old male with acute coronary syndrome who developed left main compression syndrome while waiting for a lung transplantation secondary to interstitial pneumonia, but underwent successful LMCA stenting as emergent treatment. Coronary angiography 3 months after the operation showed good stent patency in the LMCA, and the clinical course was favorable.

Exogenous adenosine triphosphate disodium administration during primary percutaneous coronary intervention reduces no-reflow and preserves left ventricular function in patients with acute anterior myocardial infarction: a study using myocardial contrast echocardiography.

BACKGROUND: It is unknown whether adenosine triphosphate disodium (ATP) administration during primary percutaneous coronary intervention (PCI) is useful in anterior acute myocardial infarction (AMI). METHODS: The study was a prospective, non-randomized, open-label trial. Primary PCI was successfully performed in 204 consecutive patients with first anterior AMI. ATP at a mean dose of 117 microg/kg/min for 45 min on an average was infused intravenously during PCI in 100 patients (Group 1). In the other 104 patients, normal saline was administered (Group 2). ST-segment resolution (STR) was estimated 90 min after recanalization. The no-reflow ratio was measured 2 weeks later, using intravenous myocardial contrast echocardiography. Left ventricular ejection fraction (LVEF), LV regional wall motion (LVRWM), and LV end-diastolic volume index (LVEDVI) were measured 6 months later. RESULTS: Baseline patient characteristics of the two groups were similar, including TIMI risk scores. Significant STR (> or =50% resolution compared to baseline) (66% versus 50%; Group 1 versus Group 2, p=0.02), no-reflow ratio (24% versus 34%, indicated by mean values, p=0.02), LVEF (61% versus 55%, p=0.0007), LVRWM (-1.56 versus -2.05, using the SD/chord, p=0.0001), and LVEDVI (60 ml/m(2) versus 71 ml/m(2), p=0.0007) were significantly better in Group 1, and the no-reflow ratio, LVEF, LVRWM and LVEDVI were significantly better in ATP-administered patients, regardless of antecedent angina or advanced age. ATP Administration was consistently identified as a significant determinant for STR, no-reflow ratio, LVEF, LVRWM, and LVEDVI. CONCLUSIONS: Intravenous ATP administration during reperfusion is an independent determinant of STR and the no-reflow ratio, and LVEF, LVRWM, and LVEDVI at 6 months after primary PCI.

Intravenous administration of adenosine triphosphate disodium during primary percutaneous coronary intervention attenuates the transient rapid improvement of myocardial wall motion, not myocardial stunning, shortly after recanalization in acute anterior myocardial infarction.

BACKGROUND AND PURPOSE: Administration of adenosine attenuates myocardial stunning after reperfusion in a canine experimental ischemic model. However, it is unknown whether administration of adenosine triphosphate disodium (ATP) during reperfusion can attenuate myocardial stunning after coronary recanalization in patients with acute myocardial infarction (MI). Therefore, we sought to elucidate the effects of ATP administration on serial changes of left ventricular systolic function before and after coronary recanalization. METHODS: In 27 patients with first ST-elevation acute anterior MI, in whom primary percutaneous coronary intervention (PCI) was completed within 10 h after symptom onset, ATP at a mean rate of 103 microg/kg/min (n=16) or normal saline (n=11) was intravenously administered for 1 h during reperfusion. Left ventricular regional wall motion within the initially severely ischemic region was serially analyzed using the standard wall motion score index (WMSI) by transthoracic echocardiography. RESULTS: Means of WMSIs were similar shortly before primary PCI in both groups (2.79 in ATP group and 2.69 in controls). They changed to 2.56 and 2.22 shortly after PCI, 2.49 and 2.39 on day 2, 2.34 and 2.30 on day 3, 2.19 and 2.25 on day 10, and 1.85 and 2.02, 6 months later, respectively. Transient improved regional wall motion within the initially severely ischemic region was observed shortly after PCI in controls (10.3% of observed segments); however, it was significantly suppressed in the ATP group (2.55%). The percent recovery of WMSI on day 10, which was defined as WMSI on day 10 normalized by improvement of WMSI for 6 months, was 63.8% in ATP group and 65.7% in controls, implying ATP administration could not reduce myocardial stunning by day 10 after primary PCI. CONCLUSIONS: The high-dose administration of ATP during primary PCI prevented transient improved wall motion shortly after coronary recanalization rather than preventing left ventricular stunning. These results suggest that ATP can prevent reperfusion injury during primary PCI.

[Prophylactic intraaortic balloon pumping preserves left ventricular systolic function in acute anterior myocardial infarction without cardiogenic shock].

OBJECTIVES: Left ventricular function and prognosis were evaluated in patients with acute myocardial infarction who underwent primary percutaneous coronary intervention supported by intraaortic balloon pumping. METHODS: Fifty-eight consecutive patients with first acute myocardial infarction were treated between July 1999 and April 2006. Twenty-five had cardiogenic shock on admission, whereas 33 did not. Patients with anterior acute myocardial infarction without cardiogenic shock were divided into the prophylactic intraaortic balloon pumping group (Group 1; n=17) and the rescue intraaortic balloon pumping group (Group 2; n=9). RESULTS: Thirty-day in-hospital mortality was 52% in cardiogenic shock patients, and 3% in non-shock patients. Baseline characteristics of non-shock anterior acute myocardial infarction were similar including Thrombolysis in Myocardial Infarction (TIMI) risk scores (5.1 and 5.0) in the two groups. However, average left ventricular ejection fraction in the convalescent stage was superior in Group 1 (48.7% vs. 37.8%, p = 0.03). Thirty-day in-hospital mortality was 0% in Group 1 and 11% in Group 2 (p = 0.34). Cox's hazard ratio in Group 2 to Group 1 was 2.38 (95% confidence intrerval; 0.84-11.1, p = 0.09) in terms of the subsequent major cardiac events. CONCLUSIONS: Prophylactic use of intraaortic balloon pumping starting prior to primary percutaneous coronary intervention preserves the convalescent left ventricular systolic function in patients with high risk for anticipated cardiac events after anterior acute myocardial infarction without cardiogenic shock.

Improvement of atrial signal-averaged electrocardiographic abnormalities after radiofrequency catheter ablation in persistent atrial flutter.

It has been reported that abnormalities of atrial conduction are present in patients with atrial flutter (AFL). We analyzed the P wave signal-averaged ECG (PSE) in patients after cardioversion of chronic AFL by radiofrequency catheter ablation (RFCA) to determine whether abnormalities of atrial conduction exist in patients with AFL and whether they recover. We studied 11 patients undergoing ablation of persistent AFL (AFL group), 11 patients with paroxysmal AFL (PAFL group), and 14 patients without any evidence of arrhythmias (control group). The PSEs were recorded 1 day, 7 days, and 1 month after RFCA. The filtered P wave duration (FPD) was calculated from the PSE recording. The FPD correlated with interatrial conduction time (r = 0.644) and left atrial dimension (r = 0.675) in combined assessment of the AFL and PAFL groups. The FPD was longer in the AFL group 1 day (165 +/- 14 ms, P < 0.001) and 1 month (150 +/- 18 ms, P < 0.05) after RFCA than in the control group (134 +/- 10 ms). Our findings suggest that atrial conduction abnormalities detected by PSE are present in patients with persistent AFL and improve 1 month after cardioversion.

Matrix metalloproteinase-9 contributes to human atrial remodeling during atrial fibrillation.

OBJECTIVES: The purpose of this study was to determine the relationship between matrix metalloproteinases (MMPs)-1, -2, and -9, and tissue inhibitors of metalloproteinases (TIMP)-1 and the atrial structural remodeling during atrial fibrillation (AF). BACKGROUND: Matrix metalloproteinases, a family of proteolytic enzymes and TIMPs, regulate the extracellular matrix turnover in cardiac tissue. METHODS: Tissue samples were obtained from 25 patients without a history of AF (regular sinus rhythm [RSR]) and 13 patients with AF (paroxysmal AF: 6, chronic AF 7) undergoing cardiac operations. We performed a western blotting analysis of the MMP-1, -2, and -9, and quantitatively analyzed the expression of the MMP-9 and TIMP-1 by real time polymerase chain reaction and ELISA. The localization of the MMP-9 was investigated by in situ zymography and immunohistochemistry. RESULTS: The active form of the MMP-9 was significantly increased in the AF group in comparison to that in the RSR group (p < 0.05), but there were no differences between the groups in the protein level of the latent form of the MMP-9 and active and latent forms of the MMP-1 and MMP-2. We also demonstrated that the expression of the MMP-9 was significantly more increased in the atria of the AF group than in that of the RSR group for both the messenger ribonucleic acid (mRNA) (AF: RSR; 1: 1.5) and protein levels (AF: RSR; 3.9 +/- 1.3 : 1.5 +/- 0.4 ng/mg atrium). The expression level of the MMP-9 was also higher in the PAF group than in the RSR group, however, the diameter of the left atrium was similar in both groups. The gelatinase activity and left atrium diameter were positively correlated (p < 0.05, R = 0.766). The relative expression of the mRNA for the monocyte chemoattractant protein-1 was higher in the AF group than in the RSR group. Immunohistochemical analysis revealed that the MMP-9 was distributed within the perivascular area and under the epicardium of the atria. CONCLUSIONS: We clearly showed that the expression of the MMP-9 increased in fibrillating atrial tissue, which may have contributed to the atrial structural remodeling and atrial dilatation during AF.

Response of the left anterior descending coronary artery to acetylcholine in patients with chest pain and angiographically normal coronary arteries.

Because atherosclerotic plaque burden affects the likelihood of plaque rupture, it is important to determine the presence and extent of atherosclerotic plaque. We hypothesized that endothelial dysfunction becomes more prominent with development of atherosclerotic plaque; therefore, we examined the relation between coronary endothelial dysfunction and the presence of atherosclerotic plaque. In 36 patients with normal coronary arteries, acetylcholine (ACh; 3 and 30 microg/min) and nitroglycerin were infused into the left coronary ostium, and the diameter of the left anterior descending (LAD) coronary artery was quantitatively measured in response to each drug. The plaque burden was measured in the same segment using intravascular ultrasonography. The plaque burden was 31.2 +/- 2.1% and correlated inversely with changes in coronary diameter induced by 3 microg/min of ACh (r = -0.754, p <0.0001), 30 microg/min of ACh (r = -0.552, p = 0.0005), and nitroglycerin (r = -0.531, p = 0.0009). Multivariate regression analysis showed that the change in coronary diameter induced by 3 microg/min of ACh was associated with plaque burden, independent of the effects of nitroglycerin-induced dilation. Receiver-operating characteristics analysis demonstrated that a cut-off value for the change in coronary diameter induced by 3 microg/min of ACh for predicting a plaque burden of >30% was 0%, with a sensitivity of 0.82 and a specificity of 0.95. These findings suggest that coronary endothelial dysfunction is correlated with atherosclerotic plaque burden, indicating that atherosclerotic plaque may be detected based on coronary endothelial function as assessed by low-dose ACh infusion.

Myocardial bridging increases the risk of coronary spasm.

BACKGROUND: Myocardial bridging (MB) has been associated with cardiac events. Whether coronary spasm is one factor contributing to those events is unknown. HYPOTHESIS: This study investigated whether the likelihood of coronary spasm is increased in patients with MB. METHODS: A spasm-provocation test was performed by infusing acetylcholine into the left coronary artery in 114 Japanese patients with chest pain. The test result was defined as positive when the diameter of the coronary artery was reduced by > or = 50% and ST-segment changes were documented. Myocardial bridging was defined as a > 15% reduction in coronary arterial diameter during systole after intracoronary injection of nitroglycerin. RESULTS: Myocardial bridging was identified in 41 patients (36%) and was located in the mid-segment of the left anterior descending coronary artery (LAD) in all patients. Patients with MB experienced coronary spasm more frequently than patients without MB (MB+: 73%; MB-: 40%, p = 0.0006). Furthermore, among patients with a positive spasm-provocation test, coronary spasm occurred more frequently in the mid-segment of the LAD in patients with MB than in those without MB (MB+: 73%; MB-: 45%, p = 0.0259). Multivariate regression analysis demonstrated that MB was a predictor of coronary spasm (odds ratio: 3.478, p = 0.0088). CONCLUSIONS: These results suggest that MB increases the risk of coronary spasm and that coronary spasm may be the proximate etiology of cardiac events associated with MB.

Five-year angiographic outcome in patients without restenosis following coronary balloon angioplasty: a comparison between non diabetic and diabetic lesions.

Few studies have investigated the long-term angiographic outcome of successful coronary balloon angioplasty (CBA) among diabetic and nondiabetic dilated lesions. The purpose of this study was to evaluate and compare the long-term (>5 years) outcomes of diabetic and nondiabetic CBA lesions which had remained patent 3-12 months after intervention. Twenty-five patients (45 lesions) with diabetes mellitus and 79 patients (138 lesions) without diabetes mellitus were enrolled as subjects. All patients who underwent CBA without restenosis within 3-12 months of the initial CBA based on follow-up angiographic evaluation were included. Quantitative coronary angiograms performed before, immediately after CBA, during the 3-12-month period (mean 4.1 +/- 1.0 months), and at or after 5 years (mean 6.4 +/- 2.0 years) were compared. There was no significant difference in the reference diameter between nondiabetic and diabetic lesions at any of the four time points studied. The minimum lumen diameter before and immediately after the procedure and at the 3-12-month follow-up did not differ significantly between the two groups. At >5-year follow-up. the minimum lumen diameter was significantly (P = 0.005) decreased in diabetic lesions. Total occlusion occurred in 9% (4/45) of the diabetic lesions compared to only 1%, (1/138) in the nondiabetic lesions (P = 0.007). Diabetic lesions showed significant (P = 0.049) narrowing between the 3-12 month period and >5-year follow-up. Fifty-one percent (18/35) of the nondiseased vessels in the diabetic patients at the time of enrollment had new stenosis during the follow-up periods. In conclusion, compared to nondiabetic lesions, patients with diabetic lesions who underwent CBA were more predisposed to have stenotic progression and total occlusion.