Kazuhiro Shinozaki

The number of leads with fragmented QRS is independently associated with cardiac death or hospitalization for heart failure in patients with prior myocardial infarction

BACKGROUND No information is currently available on the prognostic significance of the number of leads with fragmented QRS (fQRS). The objective of the study was to clarify the prognostic significance of the number of leads with fQRS in prior myocardial infarction (MI). METHODS AND RESULTS We retrospectively examined 170 patients with prior MI. The primary end point was cardiac death or hospitalization for heart failure. During a mean follow-up period of 6.4 ± 2.9 years, 37 patients developed the primary end point. Univariate Cox proportional hazards regression analyses showed that age, male gender, chronic kidney disease, anterior wall MI, number of leads with fQRS, left ventricular ejection fraction, loop diuretic use, and spironolactone use were significantly associated with the primary end point. A multivariate Cox proportional hazards regression analysis selected age (hazard ratio [HR] 1.09, 95% confidence interval [CI] 1.04-1.14, p<0.001) and the number of leads with fQRS (HR 1.33, 95% CI 1.11-1.60, p=0.002) as predictors of the primary end point. A receiver operating characteristic curve analysis showed that the presence of ≥3 leads with fQRS was most useful for distinguishing between patients with and without the primary end point. A Kaplan-Meier analysis showed a lower primary event-free rate in patients with ≥3 leads with fQRS than in those with <3 leads with fQRS. CONCLUSIONS The number of leads with fQRS, especially the presence of ≥3 leads with fQRS, is an independent predictor of cardiac death or hospitalization for heart failure in patients with prior MI.

A new electrocardiographic criterion to differentiate between Takotsubo cardiomyopathy and anterior wall ST-segment elevation acute myocardial infarction.

Several studies have examined the ability of electrocardiography to differentiate between takotsubo cardiomyopathy (TC) and anterior wall acute ST-segment elevation myocardial infarction (AA-STEMI). In those studies, the magnitude of ST-segment elevation was not measured at the J point. The American Heart Association, American College of Cardiology Foundation, and Heart Rhythm Society guidelines recommend that the magnitude of ST-segment elevation should be measured at the J point. Accordingly, the aim of this study was to retrospectively examine whether electrocardiography, using the magnitude of ST-segment elevation measured at the J point, could differentiate 62 patients with TC from 280 with AA-STEMI. Patients with AA-STEMI were divided into following subgroups: 140 with left anterior descending coronary artery occlusions proximal to the first diagonal branch (AA-STEMI-P), 120 with left anterior descending occlusions distal to the first diagonal branch and proximal to the second diagonal branch (AA-STEMI-M), and 20 with left anterior descending occlusions distal to the second diagonal branch (AA-STEMI-D). TC had a much lower prevalence of ST-segment elevation ≥1 mm in lead V(1) (19.4%) compared to AA-STEMI (80.4%, p <0.01), AA-STEMI-P (80.7%, p <0.01), AA-STEMI-M (80%, p <0.01), and AA-STEMI-D (80%, p <0.01). ST-segment elevation ≥1 mm in ≥1 of leads V(3) to V(5) without ST-segment elevation ≥1 mm in lead V(1) identified TC with sensitivity of 74.2% and specificity of 80.6%. Furthermore, this criterion could differentiate TC from each AA-STEMI subgroup, with similar diagnostic values. In conclusion, using the magnitude of ST-segment elevation measured at the J point, a new electrocardiographic criterion is proposed with an acceptable ability to differentiate TC from AA-STEMI.

Abnormal P-wave terminal force in lead V1 is associated with cardiac death or hospitalization for heart failure in prior myocardial infarction

The aim of this study was to clarify the prognostic significance of P-wave terminal force in lead V1 (PTFV1) in patients with prior myocardial infarction (MI). We retrospectively examined 185 patients with prior MI. The primary end point was cardiac death or hospitalization for heart failure. Abnormal PTFV1 was defined as PTFV1 ≥ 40 mm × ms. During a follow-up period of 6.4 ± 2.9 years, 39 patients developed the primary end point. A Kaplan–Meier analysis showed a lower primary event-free rate in 79 patients with abnormal PTFV1 than in 106 patients with normal PTFV1 (P < 0.001). When we classified 79 patients with abnormal PTFV1 into 31 with a purely negative P wave in lead V1 and 48 with a biphasic negative P wave in lead V1, the primary event-free rate did not differ between the two groups of patients. A multivariate Cox regression analysis selected age (hazard ratio (HR) 1.09, 95 % confidence interval (CI) 1.04–1.14, P < 0.001), multivessel coronary disease (HR 2.33, 95 % CI 1.02–5.28, P = 0.04), and abnormal PTFV1 (HR 2.72, 95 % CI 1.24–5.99, P = 0.01) as independent predictors of the primary end point. In conclusion, abnormal PTFV1 is an independent predictor of cardiac death or hospitalization for heart failure in patients with prior MI. The analysis of P waves in lead V1 should provide useful prognostic information in patients with prior MI.

Associations of positive T wave in lead aVR with hemodynamic, coronary, and left ventricular angiographic findings in anterior wall old myocardial infarction

BACKGROUND No information is available on the clinical significance of a positive T wave in lead aVR in myocardial infarction (MI). Accordingly, in the present study, we sought to clarify the associations of the positive T wave in lead aVR with hemodynamic, coronary angiographic, and left ventriculographic findings in anterior wall old MI. METHODS We examined 122 patients with anterior wall old MI who underwent diagnostic or follow-up cardiac catheterization including coronary angiography and left ventriculography. The patients were classified into the following 2 groups: patients with a positive (≥ 1mm) T wave in lead aVR (n=20, group A) and those without (n=102, group B). RESULTS Group A had higher pulmonary arterial, pulmonary capillary wedge, and left ventricular (LV) end-diastolic pressures and a lower cardiac index than group B. The prevalence of a long left anterior descending coronary artery (LAD) was higher in group A than in group B (60% vs 30.4%, p=0.01), and none of group A patients had an LAD that did not reach the apex. Group A had a lower LV ejection fraction than group B (36.4 ± 11.6% vs 48.4 ± 12.7%, p<0.001). CONCLUSIONS The positive T wave in lead aVR is related to severely reduced cardiac function, with an LAD wrapping the apex, in anterior wall old MI. Further studies are needed to clarify whether the positive T wave in lead aVR is associated with an adverse outcome in patients with anterior wall old MI.

Upright T waves in lead aVR are associated with cardiac death or hospitalization for heart failure in patients with a prior myocardial infarction

The aim of the present study was to clarify the prognostic significance of upright T waves (amplitude > 0 mV) in lead aVR in patients with a prior myocardial infarction (MI). We retrospectively examined 167 patients with a prior MI. The primary end point was cardiac death or hospitalization for heart failure. During a follow-up period of 6.5 ± 2.8 years, 34 patients developed the primary end point. A Kaplan–Meier analysis showed a lower primary event-free rate in patients with upright T waves in lead aVR than in those with nonupright T waves in lead aVR (P = 0.001). Univariate Cox proportional hazards regression analyses showed that age, gender, chronic kidney disease, anterior wall MI, upright T waves in lead aVR, left ventricular ejection fraction, loop diuretic use, and spironolactone use were significantly associated with the primary end point. A multivariate Cox proportional hazards regression analysis selected age [hazard ratio (HR) 1.10, 95% confidence interval (CI) 1.05–1.16, P < 0.001], upright T waves in lead aVR (HR 3.10, 95% CI 1.23–7.82, P = 0.017), and loop diuretic use (HR 4.61, 95% CI 1.55–13.67, P = 0.006) as independent predictors of the primary end point. In conclusion, the presence of upright T waves in lead aVR is an independent predictor of cardiac death or hospitalization for heart failure in patients with a prior MI. The analysis of T-wave amplitude in lead aVR provides useful prognostic information in patients with a prior MI.

Gender Differences in Symptoms During 60-Second Balloon Occlusion of the Coronary Artery

Previous investigations have demonstrated the presence of gender differences in the symptoms of angina pectoris and acute coronary syndrome. However, most of these investigations have had certain limitations, including being retrospective, an interview-related bias, a various duration of myocardial ischemia, and a lack of multivariate analysis, all of which would have affected the results. Accordingly, we prospectively examined the presence or absence of chest pain and non-chest pain symptoms during a 60-second balloon inflation in the setting of percutaneous coronary intervention, which provides a unique model of transient myocardial ischemia, in 110 men and 80 women with coronary artery disease. Chest pain and/or non-chest pain symptoms (occipital pain, jaw pain, neck/throat pain, shoulder pain, upper arm pain, back pain, and nausea) were observed during the balloon inflation in 72 men and 52 women. In the 124 patients with any symptoms during the balloon inflation, non-chest pain symptoms were more common in women than in men (31% vs 14%, p = 0.02); however, the incidence of chest pain did not differ between the men and women. After adjustment for covariables, including age, body mass index, hypertension, diabetes mellitus, current smoking, previous myocardial infarction, target vessels, β-blocker use, and calcium antagonist use, female gender remained significantly associated with non-chest pain symptoms (odds ratio 3.3, 95% confidence interval 1.2 to 9.9, p = 0.02). In conclusion, non-chest pain symptoms during the 60-second balloon occlusion of the coronary artery were more common in women than in men, supporting the presence of the gender difference in myocardial ischemic symptoms.

Washout Rate of Cardiac Iodine-123 Metaiodobenzylguanidine is High in Chronic Heart Failure Patients With Central Sleep Apnea

BACKGROUND The association between sleep-disordered breathing (SDB) assessed by polysomnography and cardiac sympathetic nerve activity (SNA) assessed by cardiac iodine-123 metaiodobenzylguanidine (123I-MIBG) imaging has not been investigated in patients with chronic heart failure (CHF). METHODS AND RESULTS We performed cardiac 123I-MIBG scintigraphy and overnight polysomnography in 59 patients with stable CHF. The patients were classified into the 3 groups: 19 with no or mild SDB (NM-SDB, apnea-hypopnea index <15); 21 with central sleep apnea (CSA), and 19 with obstructive sleep apnea (OSA). The cardiac washout rate (WR) of 123I-MIBG was obtained from initial and delayed planar 123I-MIBG images. The WR was higher in patients with CSA (54.2 + or - 11.6%) than in those with OSA (37.9 + or - 8.6%, P < .05) or NM-SDB (40.8 + or - 8.8%, P < .05). The WR correlated positively with central apnea index (rho = 0.40, P = .002). A stepwise multiple regression analysis selected CSA and plasma brain natriuretic peptide levels as independent variables associated with the WR. CONCLUSIONS The WR was higher in CHF patients with CSA than in those with OSA or NM-SDB, and CSA was independently associated with the WR, suggesting a link of CSA to increased cardiac SNA in CHF.

Reliability of ST-Segment Shifts in the Synthesized V3R–V5R Leads After Coronary Balloon Inflations During Percutaneous Coronary Intervention

Obtaining a right-chest electrocardiogram is essential for diagnosing concomitant right ventricular infarction in patients with inferior wall acute myocardial infarctions. A software program to synthesize right-chest electrocardiographic waveforms from 12-lead electrocardiographic waveforms is available in Japan. However, its reliability has not been fully investigated. Accordingly, the aim of this study was to examine the reliability of ST-segment shifts in the synthesized V3R to V5R leads. ST-segment shifts in actual and synthesized V3R to V5R leads were compared during the last 10 seconds of 131 balloon inflations while performing elective percutaneous coronary intervention in 56 patients with coronary artery disease. ST-segment shifts in the actual and synthesized V3R, V4R, and V5R leads were correlated (r = 0.96, p <0.001, r = 0.94, p <0.001, and r = 0.91, p <0.001, respectively). A Bland-Altman analysis showed that the bias between ST-segment shifts in the actual and synthesized V3R to V5R leads was -3.1, -5.4, and -4.2 μV, respectively, while the limits of agreement between the ST-segment shifts in the actual and synthesized V3R to V5R leads were -59.2 to 52.9, -61.9 to 51.1, and -59.7 to 51.3 μV, respectively. The κ coefficients for ST-segment elevation of ≥50 and ≥100 μV in the actual and synthesized V3R, V4R, and V5R leads were 0.83 and 0.81, 0.66 and 0.83, and 0.57 and 0.80, respectively. In conclusion, these results indicate that ST-segment shifts in the synthesized V3R to V5R leads have acceptable reliability, suggesting that synthesized right-chest electrocardiography can be used to diagnose concomitant right ventricular infarction in patients with inferior wall acute myocardial infarctions.

Electrocardiographic differentiation between occlusion of the first diagonal branch and occlusion of the left anterior descending coronary artery

PURPOSE We sought to electrocardiographically distinguish ST-segment elevation (STE)-acute myocardial infarction (AMI) caused by occlusion of the first diagonal branch (D1) from STE-AMI caused by occlusion of the left anterior descending coronary artery (LAD). METHODS We examined 28 patients with STE-AMI caused by D1 occlusion (G-D) and 342 with STE-AMI caused by LAD occlusion (G-L). RESULTS G-D had a higher prevalence of STE > or = 0.5 mm in each of leads I and aVL and a lower prevalence of STE > or = 1 mm in each of leads V(1) through V(6) than G-L. The prevalence of STE > or = 0.5 mm in lead aVL without STE > or = 1 mm in lead V(1) was higher in G-D (82.1%) than in G-L (9.4%, P < .01). CONCLUSION ST-segment elevation > or = 0.5 mm in lead aVL without STE > or = 1 mm in lead V(1) may be useful to distinguish STE-AMI caused by occlusion of the D1 from STE-AMI caused by occlusion of the LAD.