BACKGROUND: Several studies suggested that T-wave normalization (TWN) in exercise ECG indicates the presence of viable myocardium. But the clinical implication of this phenomenon in patients with acute myocardial infarction who received proper revascularization therapy was not determined. Precisely the aim of this study was to investigate the relationship between TWN in exercise ECG and myocardial functional recovery after acute myocardial infarction. METHODS: We studied 30 acute myocardial infarction patients with negative T waves in infarct related electrocardiographic leads and who had received successful revascularization therapy. Exercise ECG was performed 10 ~14days after infarct onset using Naughton protocol. Patients were divided into 2 groups according to presence (group I; n=14) or not (group II; n=16) of TWN in exercise ECG. Exercise parameters and coronary angiographic findings were compared between groups. Baseline and follow-up (mean 11 months) regional and global left ventricular function was analyzed by echocardiography. RESULTS: Exercise parameters were similar between groups. There was no difference in baseline ejection fraction and wall motion score between group I and II (EF; 56 +/- 12% vs 52 +/- 11%, p=ns. WMS; 21 +/- 3 vs 23 +/- 4, p=ns) and it was improved at the tenth month by similar magnitude (group I/group II, EF % change = 12 +/- 12% vs 7 +/- 6%, p=ns, WMS % change=6 +/- 6% vs 7+/- 5%, p=ns). The finding of no relation between TWN and functional recovery was observed also when the patients were analysed according to infarct location and presence or absence of Q-waves. CONCLUSION: As the exercise-induced TWN in patients with acute myocardial infarction was not related with better functional recovery of dysfunctional regional wall motion and ejection fraction, TWN does not appear to be an indicator of myocardial viability.
Aged ; Electrocardiography ; Exercise Test ; Female ; Human ; Male ; Middle Age ; Myocardial Infarction/*physiopathology/surgery ; Myocardial Revascularization

Heart Aneurysm ; mortality ; pathology ; surgery ; Humans ; Mitral Valve Insufficiency ; mortality ; physiopathology ; surgery ; Myocardial Infarction ; mortality ; physiopathology ; surgery ; Ventricular Dysfunction, Left ; pathology ; surgery

PURPOSE: We aimed to discover clinical and angiographic predictors of microvascular dysfunction using the index of microcirculatory resistance (IMR) in patients with ST-segment elevation myocardial infarction (STEMI). MATERIALS AND METHODS: We enrolled 113 patients with STEMI (age, 56+/-11 years; 95 men) who underwent primary percutaneous coronary intervention (PCI). The IMR was measured with a pressure sensor/thermistor-tipped guidewire after primary PCI. The patients were divided into three groups based on IMR values: Low IMR [<18 U (12.9+/-2.6 U), n=38], Mid IMR [18-31 U (23.9+/-4.0 U), n=38], and High IMR [>31 U (48.1+/-17.1 U), n=37]. RESULTS: The age of the Low IMR group was significantly lower than that of the Mid and High IMR groups. The door-to-balloon time was <90 minutes in all patients, and it was not significantly different between groups. Meanwhile, the symptom-onset-to-balloon time was significantly longer in the High IMR group, compared to the Mid and Low IMR groups (p<0.001). In the high IMR group, the culprit lesion was found in a proximal location significantly more often than in a non-proximal location (p=0.008). In multivariate regression analysis, age and symptom-onset-to-balloon time were independent determinants of a high IMR (p=0.013 and p=0.003, respectively). CONCLUSION: Our data suggest that age and symptom-onset-to-balloon time might be the major predictors of microvascular dysfunction in STEMI patients with a door-to-balloon time of <90 minutes.
Aged ; Angiography/*methods ; Female ; Humans ; Male ; Microcirculation ; Middle Aged ; Myocardial Infarction/physiopathology/*surgery ; Operative Time ; *Percutaneous Coronary Intervention ; Regression Analysis

OBJECTIVETo investigate whether injectable engineering heart tissue (EHT) can survive and improve heart function after transplantation into infarct area.

METHODSVentricular cardiomyocytes from 1-3 day-old Sprague-Dawley (SD) rats were isolated by using trypsin method, and then labeled and cultured. The left coronary of female SD rats was ligated to create a myocardial infarct model. Three weeks later, the qualified animals were randomized into four groups: EHT group (n = 12), which were transplanted with both cardiomyocytes and matrix; cell transplantation group (n = 12); matrix group (n = 12), control (n = 11). Four weeks after implantation, echocardiography and Langendorff model were used to assess heart function, and then the hearts were harvested for pathological examination. Meanwhile polymerase chain reaction (PCR) was performed to detect SRY gene on Y chromosome.

RESULTSThe grafted cells were identified in both EHT and cell transplantation group by either pathology or PCR. But in EHT group, transplanted cells formed more condensed tissue, and produced definite connected protein. Data of fraction shortness from echocardiography are showed as follows: EHT group, (22.82 +/- 3.44)%; cell transplantation group, (20.55 +/- 4.11)%, matrix group, (17.05 +/- 4.57)%; control, (19.80 +/- 3.98)% (P = 0.012). Langendorff examination revealed significant differences among four groups when left ventricular balloon volume was at the level of 0.06 ml, 0.08 ml and 0.10 ml, in which EHT group had the highest developed pressure and dp/dt.

CONCLUSIONIt is feasible to fabricate injectable EHT in vitro. The fabricated EHT could survive in the myocardial infarct area after transplantation in a rat model and improve heart function due to better histological configuration.

Animals ; Cell Transplantation ; methods ; Echocardiography ; Female ; Myocardial Infarction ; physiopathology ; surgery ; Myocytes, Cardiac ; transplantation ; Rats ; Rats, Sprague-Dawley ; Tissue Engineering

This study was purposed to investigate the effects of rat marrow mesenchymal stem cell (rMSC) transplantation on left ventricular (LV) function in a rat myocardial infarction model. Myocardial infarction was performed in male Lewis rats by ligating the proximal left coronary artery. Rats were randomly divided into 3 groups: sham operation group (only thoracotomy, n = 8), AMI group (DF12 injection, n = 10), rMSC group (Dil-Labeled rMSC transplantation). At 8 weeks later, the cardiac functions including left ventricular ejection fraction (LVEF), left ventricular end systolic pressure (LVESP), left ventricular end diastolic pressure (LVEDP), +dp/dtmax and -dp/dtmax were evaluated by echocardiography and cardiac catheterization. The presence and differentiation of engrafted cells were assessed. CD31 was detected by immunohistochemical staining to demonstrate neovascular formation. The results indicated that the cultured in vitro rMSC expressed CD90, CD44, CD105, CD54; did not express CD34, CD45, CD31, as compared with AMI group, rMSC group showed a significant increase of LVEF, LVESP, +dp/dtmax, -dp/dtmax and a significant decrease of LVEDP. Immunofluorescence demonstrated that some transplanted rMSCs were positive for myosin, suggesting that small number of transplanted rMSCs differentiated into cardiac-like cells. Immunostaining showed marked augmentation of capillary density in the rMSC group than that of AMI group. It is concluded that transplanted rMSCs can differentiate into cardiac-like cells and rMSC transplantation can improve LV function after myocardial infarction in rats.
Animals ; Bone Marrow Transplantation ; Male ; Mesenchymal Stem Cell Transplantation ; Myocardial Infarction ; physiopathology ; surgery ; Rats ; Rats, Inbred Lew ; Ventricular Function, Left

BACKGROUNDRotation of the left ventricular (LV) apex to the base, or LV torsion, is related to myocardial contractility and structure and has recently been recognized as a sensitive indicator of cardiac performance, but it has been difficult to measure. The recent development of 2-dimensional (2D) speckle tracking imaging (STI) may provide a powerful means of assessing LV torsion. This study was conducted to evaluate the global and regional LV twist in patients with anterior wall myocardial infarction (AMI) disease before and after revascularization by STI.

METHODS2D STI was performed in 35 AMI patients before and one month after revascularization, as well as in 32 normal controls. Left ventricular global and regional rotations were obtained at basal and apical short-axis levels; LV torsion was defined as apical rotation relative to the base. The time sequences were normalized to the percentage of systolic and diastolic duration.

RESULTSBefore revascularization, LV peak regional and global torsion in patients with AMI were significantly reduced as the result of reduced apical and basal rotation relative to those of normal control group (all P < 0.001); most significantly in the anterior and anterior-septal regions (P < 0.001); one month after revascularization, there were significant changes in peak rotation at either the base or apex relative to pre-revascularization values (all P < 0.001). Similarly, peak regional and global LV torsion were increased significantly (all P < 0.001). Global torsion inversely correlated with EDV (r = -0.605, P = 0.028) and ESV (r = -0.638, P = 0.019); and positively correlated with LVEF (r = 0.630, P = 0.021). Tight relations were also found between torsion and LV longitudinal and short axis function.

CONCLUSIONSSystolic torsion was decreased in AMI patients. Revascularization therapy can improve the LV function of the AMI patients. STI has a potential to quantify left ventricular global and segment torsion in patients with AMI, and may make the assessment more available in clinical and research cardiology.

Adult ; Aged ; Echocardiography ; methods ; Female ; Humans ; Image Interpretation, Computer-Assisted ; Male ; Middle Aged ; Myocardial Infarction ; physiopathology ; surgery ; Myocardial Revascularization ; Reproducibility of Results ; Rotation ; Ventricular Function, Left

In the era before reperfusion therapy, ventricular septal rupture complicated 1~3% of acute myocardial infarctions (AMI) usually 3-5 days after onset. Studies have reported a positive correlation between the incidence of septal perforation and total occlusion of the coronary arteries. A 70-year old female patient was referred to the emergency room with the diagnosis of acute anterior myocardial infarction (MI) and recent cerebral infarction. The coronary angiogram showed a 90% stenosis at the mid-portion of the left anterior descending artery (LAD), and the lesion was successfully treated by percutaneous coronary intervention (PCI) with stent implantation. After PCI, the anterior wall motion improved on the follow-up echocardiogram. However, on the 20th hospital day, the patient condition deteriorated suddenly with pulmonary congestion. The echocardiography revealed a 1.3 cm ventricular septal defect at the apical septum with a left-to-right shunt. We report this rare case of delayed septal rupture in a patient with patent LAD after PCI and recovery of wall motion.
Ventricular Septal Rupture/*etiology ; Time Factors ; Stents ; Myocardial Infarction/*complications/surgery ; Humans ; Heart Ventricles/*physiopathology ; Heart Septum/*physiopathology ; Female ; Angioplasty, Transluminal, Percutaneous Coronary ; Aged ; Acute Disease

BACKGROUNDSubstrate modification guided by CARTO system has been introduced to facilitate linear ablation of ventricular tachycardia (VT) after myocardial infarction (MI). However, there is no commonly accepted standard approach available for drawing these ablation lines. Therefore, the aim of the present study was to practically refine this time consuming procedure.

METHODSSubstrate modification was performed in 23 consecutive patients with frequent VTs after MI using the CARTO system. The initial target site (ITS) for ablation was identified by pace mapping (PM) during sinus rhythm and/or entrainment pacing (EM) during VT. According to the initial target site, two approaches were used. The initial target site in approach one has a similar QRS morphology as VT and an interval from the stimulus to the onset of QRS complex (S-QRS) of = 50 ms during PM in sinus rhythm or a difference of the post pacing interval and VT cycle length = 30 ms during concealed entrainment pacing of VT; The initial target site in approach two has an similar QRS morphology as VT and an S-QRS of < 50 ms during PM in sinus rhythm.

RESULTSOverall, 50 lines were performed with a length of (35 +/- 11) mm. Procedure time averaged (232 +/- 56) minutes, fluoroscopy time (10 +/- 8) minutes. Sixteen patients were initially involved into approach one. After completion of 3 +/- 1 ablation lines, no further VT was inducible in 13 patients. The remaining 3 patients were switched to use the alternative approach. However, in none of them the alternative approaches were successful. Approach two was initially used in 7 patients. After completion of 3 +/- 1 ablation lines, no further VT was inducible in only 2 patients. The remaining 5 patients were switched to approach one, which resulted in noninducibility of VT in 4 of them. The initial successful rate was significantly higher in the group of approach one compared to that in the group of approach two (13/16 patients vs 2/7 patients, P = 0.026).

CONCLUSIONSThe approach for substrate modification of VT after MI can be optimized by identifying the appropriate initial target site with specific characteristics within the zone of slow conduction. The refined approach may facilitate linear ablation of VT, and further reduce the procedure and fluoroscopy time.

Aged ; Body Surface Potential Mapping ; instrumentation ; methods ; Catheter Ablation ; methods ; Electrocardiography ; Female ; Humans ; Male ; Middle Aged ; Myocardial Infarction ; complications ; Surgery, Computer-Assisted ; methods ; Tachycardia, Ventricular ; physiopathology ; surgery

INTRODUCTIONAtherosclerotic coronary artery thrombosis is the most common cause of acute myocardial infarction.

CLINICAL PICTUREA 30-year-old lady presented with acute peripartum massive anterior ST segment myocardial infarction and cardiogenic shock. This was due to acute Stanford type A aortic dissection with the intimal flap occluding the left coronary ostium. The initial diagnosis was not apparent. Echocardiography confirmed the diagnosis.

TREATMENT AND OUTCOMEShe underwent emergency surgical repair (Bentall procedure). Pathology confirmed underlying idiopathic cystic medial degeneration.

CONCLUSIONA high index of clinical suspicion is required in acute myocardial infarction presenting without traditional cardiovascular risk factors.

Acute Disease ; Adult ; Aneurysm, Dissecting ; complications ; diagnosis ; surgery ; Aortic Aneurysm ; complications ; diagnosis ; surgery ; Echocardiography ; Electrocardiography ; Female ; Humans ; Myocardial Infarction ; etiology ; physiopathology ; Pregnancy ; Pregnancy Complications, Cardiovascular ; Shock, Cardiogenic ; etiology

PURPOSE: Coronary flow reserve (CFR) is recognized as an indicator of myocardial perfusion. The aim of this study was to assess the relationship between CFR in the non-infarcted myocardium and the incidence of major adverse cardiac events (MACEs). MATERIALS AND METHODS: 100 consecutive patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) were enrolled in the present study, and divided into MACE and non-MACE groups according to the incidence of 12-month MACEs. Left ventricular function and CFR were analyzed using two-dimensional echocardiography and myocardial contrast echocardiography at one week after PCI. Cardiac troponin I levels were assayed to estimate peak concentrations thereof. RESULTS: The MACE group was associated with lower CFR, compared to the non-MACE group (2.41 vs. 2.77, p < 0.001). In the multivariable model, CFR in the non-infarcted myocardium was an independent predictor of 12-month MACE (hazard ratio: 0.093, 95% confidence interval: 0.020–0.426, p=0.002) after adjustment for baseline demographic and clinical characteristics. CONCLUSION: CFR in the non-infarcted myocardium is a useful marker for predicting 12-month MACEs in patients with AMI undergoing primary PCI.
Aged ; Coronary Circulation/*physiology ; *Echocardiography ; Female ; Fractional Flow Reserve, Myocardial ; Humans ; Male ; Middle Aged ; Myocardial Infarction/diagnostic imaging/*physiopathology/*surgery ; Myocardial Perfusion Imaging ; Myocardium/*pathology ; *Percutaneous Coronary Intervention ; Proportional Hazards Models ; Treatment Outcome ; Ventricular Function, Left/*physiology