Persistent Atrial Fibrillation And Atrial Flutter Complicated By Tachycardiomyopathy Because Of Intermittent Conduction Through Accessory Pathway.

The term tachycardiomyopathy refers to a specific form of tachycardia-related cardiomyopathy caused by supraventricular or ventricular tachyarrhytmias that are both associated with ventricular rates higher than 120 bpm. The arrhythmias which are most frequently associated with these forms of heart disease are atrial fibrillation and atrial flutter, particularly found in the elderly population. The most frequent clinical manifestation is heart failure. In this case we are reporting a clinical case of a patient that came to our attention because of an episode of heart failure associated with atrial fibrillation and atrial flutter. The patient had also prolonged and repetitive strips of rapid conduction with wide QRS morphology. We don't know if the cause is pre excitation or ectopia. We showed that those strips of tachycardia with wide QRS, particularly when they were associated with atrial flutter, were so fast and consistent to determine the left ventricular contractile dysfunction; we showed also that those strips of wide complex tachycardia were caused by pre-excitation through an accessory right posteroseptal pathway and supported by the reentry circuit of common atrial flutter. The block of conduction through the accessory pathway and the elimination of atrial arrhythmia allowed the regression of left ventricular contractile dysfunction. We believe that this case is interesting because it shows that there is a strict continuity between sophisticated electrophysiological mechanisms and clinical manifestation.

[Neurally-mediated syncope and occupational accidents: prevention strategies and case report]. / Sincope neuromediata e infortuni sul lavoro: strategie preventive e considerazioni su un caso clinico.

A bus driver came to our observation after an occupational traffic accident due to a syncopal event. The positive result of the tilt testing demonstrated the neurally-mediated nature of the syncope. The accident involved approximately 40 people (all the bus passengers), fortunately without severe injuries or deaths. The described episode indicates the need for a procedural algorithm, commonly approved, applicable in the field of prevention, for those occupational categories with severe accident risk. Indeed, the possibility exists to identify at least a part of the subjects predisposed to neurally-mediated syncope. Fundamental steps for such screening are history taking (looking for previous events, familiarity), the physical examination (useful, for example, to exclude orthostatic hypotension or carotid sinus syncope), and, in particular, the tilt testing, a diagnostic investigation recommended for all the workers who have had a previous syncope and are at high occupational accident risk. Moreover, the reported case recalls the need to strengthen the collaboration between the cardiologist and the occupational health physician.

Coronary angioplasty in patients with unstable angina: clinical, electrocardiographic and angiographic predictors of in-hospital outcome. R.OS.A.I. Study Group.

BACKGROUND: In unstable angina early coronary arteriography is frequently performed, often followed by percutaneous revascularization with liberal use of stents. We intended to study the in-hospital outcome of patients receiving this treatment. METHODS: From April 1997 to April 1998, patients submitted to coronary arteriography due to unstable angina, and with no previous myocardial revascularization, were included in a multicenter registry. RESULTS: Out of 987 patients enrolled at 14 centers, 876 (89%) had percutaneous or surgical revascularization. Coronary angioplasty was performed in 571 patients (58%); 281 (49%) had Braunwald class IIIB or C angina. Refractory or prolonged chest pain, or both, were present in 133, 217 and 85 patients, respectively, and multivessel disease in 245 patients (43%). Stenting was performed in 486/571 cases (85%), abciximab was administered to 42 patients, and ticlopidine and/or aspirin to all. A procedural success was obtained in 96.9 % of cases. In-hospital major adverse cardiac events occurred in 29/571 patients (5.1%). Pain-related ST segment depression (44% of cases) was not predictive of outcome after coronary angioplasty. In multivariate analysis prolonged plus refractory angina (p = 0.02), an ejection fraction < 0.4 (p = 0.04), multivessel disease (p = 0.01) and--with the strongest predictive value--ad hoc angioplasty (p = 0.007) and use of > 1 stent (p = 0.0008) were all independent predictors of in-hospital adverse outcome. CONCLUSIONS: Coronary angioplasty with a liberal use of stents yields a high rate of procedural success, with few in-hospital major cardiac events also in "high risk" patients.

Angiographic follow-up after coronary implantation of the Multilink stent: a prospective observation.

BACKGROUND: A growing variety of coronary stents is becoming available on the market. Results of randomized trials may be difficult to apply to less selected patients, and experience with every device cannot be obtained in every center. Detailed information about the immediate and long-term results achieved with one device can be a helpful reference for interventional cardiologists. The aim of this study was to test the applicability and the clinical and angiographic results, both immediate and at 6 months, of the Multilink coronary stent in a cohort of unselected patients undergoing coronary angioplasty. METHODS: From March 1997 to June 1998 coronary angioplasty was performed in 391 patients in our center, with the use of stents in 339 patients. RESULTS: Three hundred and seventeen Multilink stents were successfully implanted in 295 lesions in 277 patients; an acute coronary syndrome was present in 209 cases (75%), and lesion types B2 and C accounted for 30% of lesions. In 7 cases (2.4%) the Multilink stent did not cross the lesion, and another device was implanted. Subacute stent occlusion occurred in 1 patient (0.36%) after primary angioplasty. After 6 months from the procedure, clinical follow-up data were available for 252 out of 254 patients: none had died, and angina or myocardial ischemia occurred in 25 patients (9.9%). A control angiogram was performed in 239 out of 254 patients (94%) at 178 +/- 34 days. Restenosis occurred in 44/239 patients (18.4%) and in 48/247 lesions (19.4%). In patients with vs without restenosis the original lesion was longer (p = 0.009), and diabetes mellitus was more frequent (p = 0.002), as was the use of multiple stents (p = 0.005). In single 15, 25 and 35 mm long stents restenosis occurred in 13.9, 15.5 and 46.2% of cases, respectively (p = NS). CONCLUSIONS: The Multilink stent showed a low rate of subacute occlusion (0.36%) and could be used safely also in patients with acute coronary syndromes. The use of a single, 15 or 25 mm long Multilink stent was associated with a low angiographic recurrence rate (14-16%).

Comparison of thrombolytic therapy and primary coronary angioplasty with liberal stenting for inferior myocardial infarction with precordial ST-segment depression: immediate and long-term results of a randomized study.

OBJECTIVES: The aim of the study was to compare randomly assigned primary angioplasty and accelerated recombinant tissue plasminogen activator (rt-PA), in patients with "high-risk" inferior acute myocardial infarction (ST-segment elevation in the inferior leads and ST-segment depression in the precordial leads). BACKGROUND: The ST-segment depression in the precordial leads is a marker of severe prognosis in patients with inferior myocardial infarction. The comparative outcome of treatment with primary angioplasty or lysis with accelerated rt-PA has not been investigated. METHODS: One hundred and ten patients within 6 h of symptoms were randomized to either treatment. To assess the in-hospital and 1-year outcome of both treatments the following results were compared: death or nonfatal infarction, recurrence of angina, left ventricular ejection fraction (LVEF), and the need for repeat target vessel revascularization (TVR). RESULTS: In patients treated with angioplasty (55) and rt-PA (55) the rate of in-hospital mortality and reinfarction was 3.6% versus 9.1% (p=0.4). Recurrence of angina was 1.8% versus 20% (p=0.002), new TVR was used in 3.6% versus 29.1% (p=0.0003), and the LVEF (%) at discharge was 55.2+/-9.5 versus 48.2+/-9.9 (p=0.0001). There were no hemorrhagic strokes, no emergency coronary artery bypass graft (CABG) and identical (5.5%) need for blood transfusions. At 1 year, the incidence of death, reinfarction or repeat TVR was 11% in the percutaneous transluminal coronary angioplasty (PTCA) group versus 52.7% in the rt-PA group (log-rank 22.38, p < 0.0001). CONCLUSIONS: Primary angioplasty is superior to accelerated rt-PA in terms of both myocardial preservation and reduction of in-hospital complications in patients with inferior myocardial infarction and precordial ST-segment depression. Primary angioplasty also yields a better long-term event-free survival.

[Primary angioplasty in acute inferior myocardial infarct with anterior ST-segment depression: the long-term follow-up]. / Angioplastica primaria nell'infarto miocardico acuto inferiore con sottoslivellamento anteriore del tratto ST: follow-up a lungo termine.

BACKGROUND: Concomitant anterior ST-segment depression is a marker of severe prognosis in inferior myocardial infarction. PATIENTS AND METHODS: Prospective observational study in patients with inferior acute myocardial infarction and ST-segment depression > or = 4 mm in the anterior leads, who were treated with primary angioplasty. Angiography was performed at hospital discharge and at six months, and a clinical follow-up was obtained at one year after the infarction. RESULTS: Sixty-three patients were included in the study. Pre-hospital and in-hospital delay were 147 +/- 70 minutes (20-355) and 54 +/- 11 minutes (18-80), respectively. Angioplasty was successful in all patients and 48 stents were implanted in 36 patients (57%). Angiography was performed at hospital discharge in 55 patients (87%) and showed a TIMI grade 3 coronary flow in the infarct-related artery in all cases. The left ventricular ejection fraction was 0.55 +/- 0.09 (0.4-0.8). One patient (1.6%) died before discharge, two (3.2%) had ischemic complications (one had non-fatal reinfarction, another had recurrent angina at rest), and three (4.9%) had local vascular complications. At the six-month follow-up, none of the patients had died. One had suffered reinfarction (1.6%) and another had been readmitted for recurrence of angina at rest (1.6%); none had symptoms of stable angina. The ejection fraction was 0.56 +/- 0.12 and eight patients (14%) showed angiographic restenosis. At twelve months, two patients had died (1.6%) and five (8%) had required readmission to hospital. CONCLUSIONS: Primary angioplasty yielded favorable results in this group of patients. Our data confirm the efficacy of primary angioplasty for the treatment of acute myocardial infarction, with a low rate of clinical (3.2%) and angiographic (14%) restenosis at six months, and a high rate (87%) of event-free survival at one year follow-up.

Plasma lipoprotein(a) is not a predictor for restenosis after elective high-pressure coronary stenting.

BACKGROUND: Lipoprotein(a) is a risk factor for coronary artery disease. Although it has been implicated in restenosis after balloon angioplasty, its role in restenosis within coronary stents is unknown. The aim of the study was to assess the role of plasma lipoprotein(a) as a predictor for restenosis after elective coronary stenting. METHODS AND RESULTS: Elective, high-pressure stenting of de novo lesions in native coronary arteries with Palmaz-Schatz stents was performed in 325 consecutive patients. Clinical, angiographic, and biochemical data were analyzed prospectively. Angiographic follow-up was performed at 6 months. Lipoprotein(a) levels were compared in patients with and without restenosis. Angiographic follow-up was obtained in 312 patients (96%); recurrence was observed in 67 patients (21.5%). No clinical or biochemical variable was associated with restenosis. Lipoprotein(a) level was 37.81+/-49. 01 mg/dL (median, 22 mg/dL; range, 3 to 262 mg/dL) in restenotic patients and 36.95+/-40.65 mg/dL (median, 22 mg/dL; range, 0 to 244 mg/dL) in nonrestenotic patients (P=NS). The correlations between percent diameter stenosis, minimum luminal diameter, and late loss at follow-up angiography and basal lipoprotein(a) plasma level after logarithmic transformation were 0.006, 0.002, and 0.0017, respectively. Multiple stents were associated with a higher incidence of restenosis (P=0.006), but biochemical data in these patients were similar to those treated with single stents. CONCLUSIONS: The basal plasma level of lipoprotein(a) measured before the procedure is not a predictor for restenosis after elective high-pressure coronary stenting.

Early aggressive treatment of unstable angina without on-site cardiac surgical facilities: a prospective study of acute and long-term outcome.

BACKGROUND: The early invasive diagnostic approach with extensive use of myocardial revascularization in patients with unstable angina is a matter of debate. Both the advantages of this strategy and the choice of the best candidates are controversial. The widespread applicability of this approach in Italian hospitals is also questionable, due to limited availability of facilities for interventional cardiology. METHODS: A prospective, observational study was done on a cohort of consecutive patients, who were admitted with a diagnosis of unstable angina and treated with an early aggressive approach at a center with interventional cardiology facilities without cardiac surgery. The aim of the study was to evaluate both the immediate and long-term clinical outcome of patients and the efficiency of our therapeutic approach. RESULTS: Two-hundred and two patients were enrolled and 85% were in Braunwald class III. Coronary angiography was performed in 171 patients (85%) at 2.1 +/- 2.4 days after admission: it showed one-, two- and three-vessel disease in 40, 29 and 22% of cases, respectively; 9% of patients had no severe coronary lesion. Left ventricular ejection fraction was 0.58 +/- 0.13. Medical treatment, coronary by-pass surgery and percutaneous myocardial revascularization were chosen in 36, 24 and 40% of cases, respectively. Coronary angioplasty was performed in our center in 58 (73%) of 80 patients at 6.8 +/- 5.6 days after admission and stents were used in 42 cases (74%). Overall hospital stay was 10.4 +/- 4 days. Cumulated adverse events (death and non-fatal myocardial infarction) occurred in 2.5 and 7% of patients during the initial admission and in the following year, respectively. CONCLUSIONS: An early aggressive approach to patients with unstable angina is feasible in a hospital with interventional cardiology in the absence of cardiac surgical facilities. The immediate favorable clinical results of this strategy in an intermediate-risk cohort seem to persist at one-year follow-up.

Prevalence of late potentials after myocardial infarction treated with systemic thrombolysis or primary percutaneous transluminal coronary angioplasty.

BACKGROUND: The presence of late potentials (LP) after myocardial infarction (MI) is related to an occluded infarct-related coronary artery (IRA). However, the effects of the signal-averaged electrocardiogram (SAECG) of systemic thrombolysis are contradicting. Reperfusion in the IRA is more frequently observed after primary percutaneous transluminal coronary angioplasty (PTCA) than after systemic thrombolysis. The aim of this prospective study was to compare the prevalence of LP in survivors of acute MI treated with either systemic thrombolysis or primary PTCA. METHODS: Between October 1994 and January 1997, 134 patients (pts) with acute MI were treated with reperfusion therapy within 12 hours of the onset of symptoms: seventy-four pts received systemic thrombolysis and 60 underwent primary PTCA. All pts (mean age 61 +/- 10 years, 120 males) had a control coronary angiography 9 +/- 5 and 10 +/- 4 days after acute MI, respectively. The recorded signals were amplified, averaged and filtered with bi-directional Butterworth filtering (band-pass filter range of 40-250 Hz). LPs were defined as the presence of 2 or 3 of the following criteria: filtered duration of the QRS complex > 114 ms, root mean square voltage of signals in the last 40 ms of the QRS < or = 20 mV and duration of the low amplitude signals > 38 ms. RESULTS: The two groups of pts did not differ significantly with respect to age, gender, presence of either diabetes or hypertension, site of MI, previous MI, Killip class, time to treatment, peak CK-MB level, incidence of reinfarction, extent of coronary artery disease and left ventricular ejection fraction. One hundred pts (75%) had patency (TIMI 3 grade flow) of the IRA at control coronary angiography. Twenty-seven pts (20%) had LP: 16 pts (22%) among those treated with systemic thrombolysis and 11 pts (18%) among those treated with primary PTCA (p = ns). Pts treated with primary PTCA had higher patency rates [95% (57/60) vs 58% (43/74); p = 0.00002] and less severe residual stenosis (19 +/- 15% vs 72 +/- 18%; p = 0.0001) in the IRA. LP were found in 15 pts (15%) with TIMI 3 grade flow and in 12 pts (35%) with TIMI 0-2 grade flow (p = 0.017). By multivariate analysis, including 18 clinical and electrocardiographic variables, an occluded IRA was the only independent predictor of the development of LP (Wald chi 2: 6.1453; p = 0.0132). CONCLUSION: Results of this prospective study suggest that primary PTCA alone does not reduce the prevalence of LP when compared to systemic thrombolysis. Only the patency of the IRA, as determined before the hospital discharge, affected the development of LP after acute MI.

Plasma activity and insertion/deletion polymorphism of angiotensin I-converting enzyme: a major risk factor and a marker of risk for coronary stent restenosis.

BACKGROUND: Tissue proliferation is almost invariably observed in recurrent lesions within stents, and ACE, a factor of smooth muscle cell proliferation, may play an important role. Plasma ACE level is largely controlled by the insertion/deletion (I/D) polymorphism of the enzyme gene. The association among restenosis within coronary stents, plasma ACE level, and the I/D polymorphism is analyzed in the present prospective study. METHODS AND RESULTS: One hundred seventy-six consecutive patients with successful, high-pressure, elective stenting of de novo lesions in the native coronary vessels were considered. At follow-up angiography, recurrence was observed in 35 patients (19.9%). Baseline clinical and demographic variables, plasma glucose and serum fibrinogen levels, lipid profile, descriptive and quantitative angiographic data, and procedural variables were not significantly different in patients with and without restenosis; mean plasma ACE levels (+/-SEM) were 40.8+/-3.5 and 20.7+/-1.0 U/L, respectively (P<.0001). Diameter stenosis percentage and minimum luminal diameter at 6 months showed statistically significant correlation with plasma ACE level (r=.352 and -.387, respectively P<.001). Twenty-one of 62 patients (33.9%) with D/D genotype, 13 of 80 (16.3%) with I/D genotype, and 1 of 34 (2.9%) with I/I genotype showed recurrence; the restenosis rate for each genotype is consistent with a codominant expression of the allele D. CONCLUSIONS: In a selected cohort of patients, both the D/D genotype of the ACE gene, and high plasma activity of the enzyme are significantly associated with in-stent restenosis. Continued study with clinically different subsets of patients and various stent designs is warranted.

[Role of spectral turbulence analysis of ECG in predicting risk of arrhythmia after myocardial infarction]. / Ruolo dell'analisi della turbolenza spettrale dell'ECG mediato nella stratificazione del rischio aritmico dopo infarto miocardico.

BACKGROUND: Spectral turbulence analysis (STA) of the signal-averaged electrocardiogram (SAECG) is a recently described frequency-domain analysis evaluating the changes in the wave front velocity in the QRS complex as a whole. In this study we prospectively assessed the role of STA in predicting arrhythmic events [(EA): ventricular tachycardia, ventricular fibrillation and sudden death] relative to ejection fraction (EF), complex ventricular arrhythmias (CVA) on Holter monitoring and site of myocardial infarction (MI) in 266 patients (pts) (209 M; 57 F; mean age 62.3 +/- 10.3)-14 with bundle branch block-surviving an acute MI. METHODS: SAECG was recorded in all pts 13 +/- 3 days after MI. STA was performed by using a PC software implementing the algorithm proposed by Kelen. The conventional parameters of STA (inter-slice correlation mean, inter-slice correlation SD, low-slice correlation ratio and spectral entropy) were calculated separately for each orthogonal lead (X, Y and Z) and their average (X + Y + Z). Ejection fraction was assessed in 241 pts and Holter recordings were analyzed in 195 pts 13 +/- 4 and 13 +/- 5 days after MI, respectively. RESULTS: During a mean follow-up of 13 +/- 10 months, there were 20 (7.5%) AE: 9 pts had sustained ventricular tachycardia, two had cardiac arrest due to ventricular fibrillation and 9 died suddenly. In 41% of pts STA was abnormal. STA sensitivity was 65%, specificity 61%, positive predictive value 12%, negative predictive value 96%, relative risk (RR) 2.67 (95% confidence bounds = 1.1-6.48; p = 0.023). Sensitivity, specificity, positive predictive value and RR for EF and CVA were 65, 78, 21%, 6.5 and 64, 66, 10%, 3.4, respectively. Abnormal STA was present in 46% of pts with anterior MI and in 42% of pts with inferior MI (ns). Sensitivity, specificity and RR were 88, 58% and 7.95 (p = 0.015) for anterior MI and 50, 59% and 1.41 (p = ns) for inferior MI. CONCLUSION: The value of STA of the SAECG is poor when performed two weeks after MI. STA theoretical advantages over time-domain analysis of the SAECG were not verified in our study.

[Effects on high resolution electrocardiogram of coronary angioplasty in acute myocardial infarct]. / Effetti sull'elettrocardiogramma ad alta risoluzione dell'angioplastica coronarica nell'infarto miocardico acuto.

BACKGROUND: The lower prevalence of ventricular late potentials (LPs) in signal-averaged electrocardiograms (SAECG) observed in patients (pts) treated with systemic thrombolysis, as compared with SAECGs in conventionally treated pts, has been attributed to the patency of the infarct-related artery. Mechanical reperfusion, achieved by means of either primary or rescue percutaneous transluminal coronary angioplasty (PTCA), is associated with higher permeability rates and reduced residual stenosis in the infarct-related artery, when compared to systemic thrombolysis. The aim of this retrospective study was to assess the prevalence of LPs in pts recovering from a first high-risk acute myocardial infarction (AMI) treated with primary or rescue PTCA. METHODS: Fifty-nine pts (48 pts with clinical signs or electrocardiographic evidence of high-risk AMI or in whom systemic thrombolysis was inadvisable, and 11 pts in whom systemic thrombolysis failed) underwent emergency PTCA within 10 hours of the onset of symptoms. All pts (mean age 61 +/- 9 years, 48 M) were monitored via coronary angiography 9 +/- 4 days after AMI. The SAECG was obtained 10 +/- 4 days after AMI. LPs were defined as the presence of 2 or 3 of the following criteria: filtered duration of the QRS complex > 114 ms, duration of the low amplitude signals > 38 ms and mean square-root voltage of signals in the last 40 ms of the QRS < or = 20 microV. RESULTS: Primary and rescue PTCA were performed 3 +/- 1.7 and 6.3 +/- 2 hours after AMI, respectively (p = 0.000). Fifty-six pts (95%) had patency (TIMI 3 grade flow) of the infarct-related artery (mean residual stenosis: 18.3 +/- 14.2%) confirmed by control coronary angiography, while the infarct-related artery was occluded in three pts. Sixteen out of 59 pts (27%) had LPs: 14/56 (25%) with TIMI 3 grade flow and 2/3 (67%) with TIMI 0 grade flow. Pts with and without LPs were comparable for age, sex, infarct location, Killip Class, mean peak CK-MB, time to control coronary angiography, time to SAECG, left ventricular ejection fraction, presence of multivessel disease, infarct-related artery and mean residual stenosis in infarct-related artery. LPs were observed more frequently after rescue PTCA than after primary PTCA (64 vs 19%; p = 0.005). Time to treatment was significantly longer in pts with LPs than in those without (4.9 +/- 2.6 vs 3.2 +/- 1.7 hours; p = 0.025). Multivariate analysis indicated that the type of PTCA (primary vs rescue PTCA) was the only independent predictor for the development of LPs. CONCLUSION: In this study, the prevalence of LPs in pts with patency of the infarct-related artery after primary or rescue PTCA was surprisingly high. Delay to treatment and type of PTCA affected the presence of LPs. The association between infarct-related artery status and prevalence of LPs has not been analyzed, due to the low number of pts with coronary artery occlusion in the control coronary angiography.

Time domain signal-averaged electrocardiogram in predicting arrhythmic events after myocardial infarction: role of the duration of the filtered QRS complex.

Several studies showed that time domain analysis of the signal-averaged ECG may identify groups of patients with low and high risk for arrhythmic events after myocardial infarction (MI). However, the signal averaging methods were not uniform and the definition of abnormal signal-averaged ECG was empiric. To identify the best quantitative signal-averaged variable in predicting arrhythmic events (sustained ventricular tachycardia, ventricular fibrillation and witnessed, instantaneous death) 262 patients surviving acute MI were prospectively evaluated. Twelve clinical variables, left ventricular ejection fraction (LVEF), complex ventricular arrhythmias (CVA) on Holter monitoring and three conventional signal-averaged variables (either at 25-250 or 40-250 Hz) were entered in a Cox proportional hazards regression model. During a mean follow-up of 20.3 +/- 13.7 months 16 (6.1%) patients had arrhythmic events. All six signal-averaged variables were independent predictors of arrhythmic events and the filtered QRS duration (fQRSD) > or = 120 ms at 40 Hz high pass filtering resulted the most predictive. In a regression analysis, including the best signal-averaged variable, LVEF and CVA, only fQRSD > or = 120 ms at 40 Hz and LVEF independently predicted arrhythmic events. Sensitivity, specificity, positive predictive value and odds ratio for fQRSD > or = 120 ms at 40 Hz were 63, 90, 29 and 11%, respectively, and for the combination of fQRSD > or = 120 ms at 40 Hz and LVEF < 40%, were 73, 95, 47 and 39%, respectively. In conclusion, the fQRSD > or = 120 ms at 40 Hz best predicts arrhythmic events in the post-infarction period. The combination of signal-averaged ECG and LVEF is recommended to stratify patients at risk of arrhythmic events after MI.

[The use of a check list for quality assurance of the treatment of acute myocardial infarction in the coronary care unit]. / Uso di un registro per il controllo di qualità del trattamento dell'infarto miocardico acuto in unità coronarica.

UNLABELLED: The implementation of Quality Assurance programs for the treatment of acute myocardial infarction in the Cardiac Intensive Care Unit may be specially important. In fact several therapeutic options are available in these patients, and delay in treatment must be as short as possible. A Quality Assurance program has been started in our center with a registry of all patients admitted within 24 hours of onset of acute myocardial infarction. PATIENTS AND METHODS: The following data were recorded: 1) indicators of Organization: pathway to admission, pre-hospital and in-hospital delay; 2) Process Indicators: duration of hospital stay, initial choice of therapy (conservative, intravenous lysis, primary angioplasty), and further diagnostic and interventional procedures; 3) Outcome Indicators: mortality and complications during admission, and 6-12 months follow-up. RESULTS: Since february 1994 to August 1995, 211 consecutive patients were included in the registry; 156 were male, mean age 66 years. Mean pre-hospital delay was 286 minutes. Admission was decided by a physician in 99 cases and by the patient him/herself in 112 cases; pre-hospital delay was 390 min. In the former group, and 194 min. In the latter (p < .001). Mean in-hospital delay was 61 minutes. Conservative treatment, intravenous lysis, and primary angioplasty were chosen by the attending cardiologist in 89 patients (group A), 69 patients (group B), and 53 patients (group C) respectively. The latter group included patients with highest risk on the basis of clinical and electrocardiographic characteristics. In-hospital mortality was 17, 7 and 9% In the 3 groups, respectively. An echocardiogram and coronary angiography were performed before discharge in 81% and 57% of patients, respectively. The mean duration of hospital stay was 11 days, irrespective of the initial therapeutic choice. CONCLUSIONS: A registry for patients with acute myocardial infarction provides information which is essential in the evaluation of therapeutic protocols; it may also help in improving the cooperation between the Emergency Department, the attending cardiologists, and the family physicians.

Reproducibility of the spectral turbulence analysis of the signal-averaged electrocardiogram.

Spectral turbulence analysis (STA) of the signal-averaged electrocardiogram (SAECG) is a recently proposed technique to identify patients with ventricular tachycardia as well as patients at risk for arrhythmic events after acute myocardial infarction (MI). The short-term reproducibility of this technique has been previously reported; our study evaluates the reproducibility of STA by shifting the reference points. Twenty patients with acute MI were recruited. SAECG was recorded 13 days after onset of the acute MI. Unfiltered data were transferred and analyzed by personal computer software for spectral turbulence analysis according to the standard condition; reference points of the segment of interest were shifted from QRS offset -10 ms and QRS onset -10 ms to QRS offset +10 ms and QRS onset +10 ms, step 2 ms. Thus, 10 analyses were computed. Reproducibility of the results was calculated using the coefficient of variation (CV) and the relative error (RE). The reproducibility of the classification (RC) was defined as the percentage of the identical classification compared with the standard segment. CV of the intersegment correlation standard deviation was statistically higher than the other parameters regardless of the lead considered. RE was not different in each parameter and in each lead. RC was > 90% in all parameters, except in spectral entropy which showed an RC > 80%. Reproducibility of the STA introducing a temporal shift in the analyzed segments was high in all considered parameters.

[A study of the variations in myocardial perfusion induced by systemic thrombolysis in acute myocardial infarct using sequential scintigraphy with 201-thallium]. / Studio delle variazioni di perfusione miocardica indotte dalla trombolisi sistemica nell'infarto miocardico acuto mediante scintigrafia sequenziale con tallio 201.

To assess scintigraphic changes induced by intravenous streptokinase therapy, serial rest redistribution thallium-201 perfusion imaging was performed in 62 patients with acute myocardial infarction lasting less than 6 hours. Twenty-seven patients randomized to treatment with intravenous streptokinase (group A) and 35 to conventional therapy (group B) underwent thallium-201 scintigraphy as soon as possible after admission to the coronary care unit (early study). Regional myocardial perfusion was assessed using thallium-201 scintigraphy 7-9 days later in each patient (late study). The size of the perfusion defect was evaluated using a semi-quantitative score. The size of the perfusion defect decreased in serial scans in both group A (preintervention score: 12.1 +/- 6.8; redistribution score: 11.4 +/- 6.8; late study: 8.8 +/- 7.0) and group B (12.8 +/- 6.5; 12.3 +/- 6.7; 10.6 +/- 7.5, respectively). No statistical difference in myocardial perfusion was found between the two groups, on late study. Peak serum creatine kinase MB (CKMB) was earlier in group A than in group B (1030.8 +/- 326.6 vs 1361.0 +/- 271.1: p less than 0.001). The fast CKMB release group (onset of symptoms-peak of CKBM less than or equal to 900 minutes) exhibited higher thallium-201 uptake when compared to the slow CKMB release group, at the time of late study (perfusion defect score: 6.1 +/- 5.7 vs 10.7 +/- 7.3: p = 0.03). Reversibility was observed in 21/62 patients (34%). Reversibility corresponded to unchanged or improved perfusion defect score on late study in 18/21 patients (86%). Nevertheless 20/41 (49%) patients not showing redistribution of thallium-201 within pre-treatment defect had an improvement in regional perfusion on late study. Reversibility was observed in 9/14 (64%) patients with fast CKMB release and in 12/47 (26%) patients with slow CKMB release. We conclude that the early peak of CKMB is associated with a higher uptake of thallium-201 on late study. Furthermore, the reversibility of perfusion defect on redistribution imaging forecasts evolution of scintigraphic perfusion, but, when this is not present, it doesn't rule out late improvement of thallium-201 myocardial uptake. The low sensitivity and specificity of redistribution imaging and the procedure related delay in instituting therapy make thallium-201 scintigraphy unreliable in the evaluation of myocardial reperfusion following thrombolysis.

[Risk stratification after uncomplicated myocardial infarct: the usefulness of the echocardiographic-dipyridamole test]. / Stratificazione del rischio dopo infarto miocardico non complicato: utilità del test eco-dipiridamolo.

To assess the value and safety of echo-dipyridamole test in risk stratification soon after an uncomplicated acute myocardial infarction, 56 consecutive patients were enrolled in a prospective study with a 1-year follow-up period for new coronary events. Echo-dipyridamole and symptom-limited ECG stress test were performed respectively 14 to 20 days and 4 to 5 weeks after acute event. Echo-dipyridamole test was performed administering 0.84 mg/kg iv of the drug in 10 min: any worsening of left ventricular regional wall motion was considered as a positive test. Up to December 1989, 43 out of 56 patients had their follow-up period completed: the infarction was anterior in 13 (30%), inferior in 22 (51%), non-Q wave in 8 (19%); mean age was 55 +/- 10; basal echocardiographic ejection fraction was 52 +/- 6%. There were no major complications during echo-dipyridamole test. Coronary events occurred in 7 patients (16%): reinfarction in 3, angina in 4; there were no cardiac deaths. A positive echo-dypiridamole test was observed in 12/43 patients (28%); sensitivity versus coronary events was 43%, specificity 75%, negative predictive value 87%. Ten out of 43 patients (23%) had positive and 9/43 (21%) non valuable ECG stress test: sensitivity versus coronary events was 50%, specificity 75%, predictive negative value 88%. The 2 tests showed no significant difference in detecting patients at risk of future coronary events.(ABSTRACT TRUNCATED AT 250 WORDS)

Study of the hydrolysis and ionization constants of Schiff base from pyridoxal 5'-phosphate and n-hexylamine in partially aqueous solvents. An application to phosphorylase b.

Formation and hydrolysis rate constants as well as equilibrium constants of the Schiff base derived from pyridoxal 5'-phosphate and n-hexylamine were determined between pH 3.5 and 7.5 in ethanol/water mixtures (3:17, v/v, and 49:1, v/v). The results indicate that solvent polarity scarcely alters the values of these constants but that they are dependent on the pH. Spectrophotometric titration of this Schiff base was also carried out. We found that a pKa value of 6.1, attributed in high-polarity media to protonation of the pyridine nitrogen atom, is independent of solvent polarity, whereas the pKa of the monoprotonated form of the imine falls from 12.5 in ethanol/water (3:17) to 11.3 in ethanol/water (49:1). Fitting of the experimental results for the hydrolysis to a theoretical model indicates the existence of a group with a pKa value of 6.1 that is crucial in the variation of kinetic constant of hydrolysis with pH. Studies of the reactivity of the coenzyme (pyridoxal 5'-phosphate) of glycogen phosphorylase b with hydroxylamine show that this reaction only occurs when the pH value of solution is below 6.5 and the hydrolysis of imine bond has started. We propose that the decrease in activity of phosphorylase b when the pH value is less than 6.2 must be caused by the cleavage of enzyme-coenzyme binding and that this may be related with protonation of the pyridine nitrogen atom of pyridoxal 5'-phosphate.