Cryptogenic Stroke In The Context of Pandemic-Related Stress: The Role of Arterial Hemodynamics.

BACKGROUND: Up to 45% of ischemic strokes are cryptogenic, which is an impediment to proposing preventative measures. In this investigation we aimed to study underlying heart arrhythmias in patients with cryptogenic stroke, taking into consideration the context of the COVID-19 pandemic and stressful lockdown conditions. SUBJECTS AND METHODS: In this cross-sectional study we observed 52 patients with cryptogenic stroke >1 month after acute presentation, and a control group consisting of 88 patients without stroke. All patients undewent the laboratory and instrumental investigation consisting of the following: lipid spectrum; hemostasiograms; hemoglobin A1c; transthoracic or/and transesophageal echocardiography; 24-hours monitoring of ECG; computer tomography or magnetic resonance imaging of the brain. We studied the hemodynamics of the common carotid arteries using Doppler ultrasound imaging and digital sphygmography (SG). RESULTS: The groups were indentical with respect to the preponderance of study parameters (sex, age, comorbidities, instrumental and laboratory data). The ischemic stroke group had a statistically significant difference in the prevalence of the first type of extrasystolic arrhythmia according to our gradation of extrasystoles, which are ventricular systoles of extrasystolic contraction appearing before the transmitral blood flow peak (peak E in echocardiography). We observed that earlier ventricular systoles of extrasystole in the cardiac cycle predicted for greater growth of hemodynamic and kinetic parameters. Calculating the indices of a four-field table established the significant relationship between the moment of appearance of extrasystolic ventricular contraction in the cardiac cycle and the risk for cryptogenic stroke (normalized value of the Pearson coefficient (C`) of the two paramaters was 0.318). CONCLUSIONS: Extrasystolic arrhythmia appeared as an additional risk factor of earlier stroke. The most dangerous type of arrhythmia was when the ventricular contraction of the extrasystole appeared before the transmitral blood flow peak in the cardiac cycle. This observation could present a risk-marker for brain-related cardiovascular complications such as stroke, which might be patients suffering from different internal diseases, especially in the context of environmental stress conditions of the current pandemic and its related lockdown measures.

Influence of irregular heart rhythm on radiation exposure, image quality and diagnostic impact of cardiac computed tomography angiography in 4,339 patients. Data from the German Cardiac Computed Tomography Registry.

BACKGROUND: Coronary computed tomography angiography (coronary CTA) provides non-invasive evaluation of the coronary arteries with high precision for the detection of significant coronary artery disease (CAD). AIM: To investigate whether irregular heart rhythm including atrial fibrillation and premature beats during data acquisition influences (i) radiation and contrast media exposure, (ii) number of non-evaluable coronary segments and (iii) diagnostic impact of coronary CTA. METHODS: Twelve tertiary care centers with ≥64 slice CT scanners and ≥5 years of experience with cardiovascular imaging participated in this registry. Between 2009 and 2014, 4339 examinations were analysed in patients who underwent clinically indicated coronary CTA for suspected CAD. Clinical and epidemiologic data were gathered from all patients. In addition, clinical presentation, heart rate and rhythm during the scan, Agatston score, radiation and contrast media exposure and the diagnostic impact of coronary CTA were systematically analysed. RESULTS: Of 4339 patients in total, 260 (6.0%) had irregular heart rhythm, whereas the remaining 4079 (94.0%) had stable sinus rhythm. Patients with irregular heart rhythm were older (63.2 ± 12.5yrs versus 58.6 ± 11.4yrs. p < 0.001), exhibited a higher rate of pathologic stress tests before CTA (37.1% versus 26.1%, p < 0.01) and higher heart rates during CTA compared to those with sinus rhythm (62.5 ± 11.6bpm versus 58.9 ± 8.5bpm, p < 0.001). Both contrast media exposure and radiation exposure were significantly higher in patients with irregular heart rhythm (90 mL (95%CI = 80-110 mL) versus 80 mL (95%CI = 70-90 mL) and 6.2 mSv (95%CI = 2.5-11.7) versus 3.3 mSv (95%CI = 1.7-6.9), p < 0.001 for both). Coronary CTA excluded significant CAD less frequently in patients with irregular heart rhythm (32.9% versus 44.8%, p < 0.001). This was attributed to the higher rate of examinations with at least one non-diagnostic coronary segment in patients with irregular heart rhythm (10.8% versus 4.6%, p < 0.001). Subsequent invasive angiography could be avoided in 47.2% of patients with irregular heart rhythm compared to 52.9% of patients with sinus rhythm (p = NS), whereas downstream stress testing was recommended in 3.2% of patients with irregular heart rhythm versus 4.0% of patients with sinus rhythm (p = NS). CONCLUSION: A significant number of patients scheduled for coronary CTA have irregular heart rhythm in a real-world clinical setting. In such patients, heart rate during coronary CTA is higher, possibly resulting in (i) higher radiation and contrast agent exposure and (ii) more frequent coronary CTA examinations with at least one non-diagnostic coronary artery segment. However, this does not seem to lead to increased downstream stress testing or subsequent invasive procedures.

Electrophysiological relation between the superior vena cava and right superior pulmonary vein in patients with paroxysmal atrial fibrillation.

INTRODUCTION: The superior vena cava (SVC) is a main source of nonpulmonary vein (PV) ectopies initiating atrial fibrillation (AF). Empiric SVC isolation may improve rhythm outcomes after catheter ablation of AF. Because the SVC passes immediately adjacent to the right superior PV (RSPV), an electrophysiological relation could be present between the two structures. The present study aimed to estimate the interrelation between the SVC and RSPV by evaluating arrhythmogenic activities observed during catheter ablation of AF. METHODS AND RESULTS: Study subjects comprised 121 consecutive patients referred for catheter ablation of paroxysmal AF. Isoproterenol infusion was used to induce ectopies and AF. Patients were divided into two groups depending on the presence of arrhythmogenic SVC: arrhythmogenic-SVC (A-SVC) and nonarrhythmogenic SVC (Non-A-SVC) groups. The prevalence of females was higher and body surface area was smaller in the A-SVC group (N = 22) than Non-A-SVC group (N = 99). Arrhythmogenic activities were observed in 60 (49%) RSPVs, 24 (20%) right inferior PVs, 72 (59%) left superior PVs, and 31 (25%) left inferior PVs. Arrhythmogenic RSPVs were more prevalent in the A-SVC group than Non-A-SVC group (86% vs. 41%, P = 0.0001), whereas these prevalences in the other three PVs were not different between groups (P >0.3). In multivariable analysis, arrhythmogenic RSPV was the only independent predictor of arrhythmogenicity of the SVC (OR, 8.53; 95% CI 2.31-31.46; P = 0.001). CONCLUSIONS: An electrophysiological interrelation may be present between the SVC and RSPV in patients with paroxysmal AF. Semiempiric SVC isolation limited to patients with an arrhythmogenic RSPV may be a more efficient treatment strategy.

[Arterial hypertension in black subjects over 50 years of age in Lomé: epidemiological aspects and evaluation of cardiovascular risk (prospective and longitudinal study of 1485 patients)]. / Hypertension artérielle du sujet noir âgé de 50 ans et plus a Lomé : aspects épidémiologiques et évaluation du risque cardiovasculaire (Étude prospective et longitudinale de 1485 patients).

INTRODUCTION: High blood pressure is a public health problem for which the assumption of responsibility remains especially difficult in older subjects. Generally, it is associated with other cardiovascular risk factors. The objective of this study is to determine the prevalence of high blood pressure in older subjects in a particular environment and to evaluate the cardiovascular risk among these patients. METHODOLOGY: This is a longitudinal exploratory study undertaken on 1485 hypertensive subjects of 50 years of age or older, selected from 1999 patients received in three health professional training centers of the community of Lomé, between June 1, 2004 and June 30, 2007. Information had been collected using a card of investigation. Classifications of high blood pressure were those of the JVCVII and the European Society of Cardiology. The data analysis had been made by computer tools. RESULTS: The prevalence high blood pressure was of 74.29%. We had noted a female prevalence (63.8%) with a sex ratio of 0,57 and one middle age of 62.08±9.3 years. Dyspnea (45.9%), chest pains (16.2%) and palpitations (13.2%) were the principal found symptoms. The various listed risk factors were: dyslipidemia (58.1%), obesity (36.12%), alcoholism (16.7%) and diabetes (10.6%). The complications were cardiac (87.81%), ocular (79.8%), renal (19.86%), neurological (4.92%) and arterial (0.99%). The cardiovascular risk was very high at 58.05% of the patients. The mortality rate was of 1.9%. CONCLUSION: High blood pressure is the most frequent cardiovascular risk factor in our country from 50 years of age. Assumption of responsibility for it is by information, education of the population and requires the mobilization of all the social components.

Ectopy in trauma patients: cautions for use of heart period variability in medical monitoring.

INTRODUCTION: Heart period variability measurements have been proposed for use in early prediction of mortality or the requirement for lifesaving interventions in trauma patients. However, the presence of even one ectopic beat (EB) and/or electromechanical noise compromises the accurate calculation of heart period variability. We tested the hypothesis that ECGs from trauma patients exhibit a greater frequency of EBs than healthy human research subjects. METHODS: Continuous ECGs were recorded in 20 healthy human subjects at rest, 108 healthy human subjects undergoing experimentally induced progressive central hypovolemia (via lower body negative pressure, LBNP), and 245 trauma patients. The proportions of subjects/patients with at least one EB were identified in each group. RESULTS: ECG waveforms from 20% and 18% of healthy human subjects at rest or undergoing LBNP, respectively, contained at least one EB. ECG waveforms from 36% of the trauma patients were found to contain either EBs (35%) or electromechanical noise (1%). CONCLUSIONS: A significant number of EBs occur in healthy subjects both at rest and during progressive reduction in central blood volume, and trauma is associated with a near doubling of this incidence. As both EBs ' and noise result in invalid heart period variability calculations, these metrics as currently calculated could not be used in approximately 36% of trauma patients. The limited use in nearly two of every five trauma patients indicate that it is unlikely that continuous heart period variability measurements could substantially improve pre-hospital or emergency room decision-support in trauma.

Protective effects of estrogen against reperfusion arrhythmias following severe myocardial ischemia in rats.

BACKGROUND: Female sex hormones may have protective effects against arrhythmias, including reperfusion arrhythmias (RAs), but the mechanisms are still not completely known. METHODS AND RESULTS: Serial changes in rat hearts (rhythm, apoptosis and the its infuencing factors; cardiac vinculin mRNA expression and connexin43 (Cx43) dephosphorylation) were examined during periods of ischemia-reperfusion with and without estrogen treatment. After reperfusion, although the incidence of arrhythmias became higher in both the vehicle-group and estrogen-group, compared with the ischemia period, estrogen prevented reperfusion-induced upregulation of the incidence of arrhythmias, especially ventricular premature beats (VPB) and ventricular tachycardia (VT). The duration of VT and fibrillation, and the number of VPB and VT, were all significantly decreased in the estrogen-group. The expression of cardiac vinculin mRNA decreased significantly in the vehicle-group but not in the estrogen-group. Cx43 dephosphorylation and myocyte apoptosis increased in both groups, but the values for the estrogen-group were all markedly lower than those for the vehicle-group. A selective estrogen receptor (ER) beta agonist prevented reperfusion-induced upregulation of the incidence of both VPB and VT significantly; a selective ERalpha agonist had no significant influence. CONCLUSIONS: Estrogen can protect the heart against RAs, at least in part, mediated through gap junctions. Upregulation of ERbeta but not ERalpha mediated most of the estrogen-induced cardioprotection against RA.

[Peculiar physiological reactions to +Gx loads of nonprofessional members of short-term missions to the ISS].

Physiological reactions to +Gx loads of 10 nonprofessional members of 8 to 12-d. missions to the ISS some of whom had partial health defciency were compared with data about space station MIR cosmonauts (n=10) who participated in flights of similar duration but were qualified as essentially healthy. Age of the ISS visitors varied between 29 and 60 years, whereas the MIR cosmonauts were 31 to 49 years old. Based on analysis of objective information, the ISS visitors were distinguished by much more pronounced sinus tachycardia and tachypnea during insertion and re-entry. There were several instances of pre-launch extrasystole arrhythmias that persisted during insertion and were, as a rule, more serious during re-entry. Also, descent from orbit caused more frequent cardiac rhythm disturbances, polymorphism and severity in these space flyers in comparison with the MIR cosmonauts. Particularly grave ECG deviations were observed in two 60-y.o. crew members. However, all these disturbances were episodic by character. These results suggest that development of individual programs of medical risk mitigation for nonprofessional flyers to the ISS should give regard for the status of cardiac rhythm regulation as re-entry g-loads may affect ECG dramatically. Besides, the analysis highlighted the necessity of more rigorous selection of aged candidates for ISS missions with partial health deficiency

Diabetes mellitus and Turner syndrome.

Noninsulindependent diabetes mellitus is 2-4 times more prevalent in Turner subjects as compared to normal females, and tends to develop at a younger age, but it is usually mild and responsive to weight loss or monotherapy. The primary pathogenic event is beta cell dysfunction, but insulin resistance also plays a central role and is worsened by the presence of hypertension, obesity and dyslipidemia which are common in Turner syndrome. We present the case of a 30 year-old female patient with short stature, 141cm (<-- 2.5 SD), overweight 51kg, waist circumference 79cm, triangular facies, downslanting palpebral fissures, low set ears, short neck, secondary amenorrhea, palpitations, a history of polyuria, polydypsia of three months duration and a fasting morning glucose of 260 mg/dL. Cardiac and renal defects were excluded, hormonologic evaluation was consistent with hypergonadotropic hypogonadism (FSH 65 mUI/mL) and primary hypothyroidism (TSH 5.68 microUI/mL) and karyotype was 45,XO. She also had hypercholesterolemia (247 mg/dL), hypocalcemia (8 mg/dL), mild elevation of hepatic enzymes (ALAT 51 U/L) and osteopenia (Tscore--2.22). Glycaemic control was achieved with diet only; therapy consisted of hormone replacement theraphy, thyroxine and beta blockers.

K(ATP) channel activation reduces the severity of postresuscitation myocardial dysfunction.

Postresuscitation myocardial dysfunction has been recognized as a leading cause of the high postresuscitation mortality rate. We investigated the effects of ischemic preconditioning and activation of ATP-sensitive K(+) (K(ATP)) channels on postresuscitation myocardial function. Ventricular fibrillation (VF) was induced in 25 Sprague-Dawley rats. Cardiopulmonary resuscitation (CPR), including mechanical ventilation and precordial compression, was initiated after 4 min of untreated VF. Defibrillation was attempted after 6 min of CPR. The animals were randomized to five groups treated with 1) ischemic preconditioning, 2) K(ATP) channel opener, 3) ischemic preconditioning with K(ATP) channel blocker administered 1 min after VF, 4) K(ATP) channel blocker administered 45 min before induction of ischemic preconditioning, and 5) placebo. Postresuscitation myocardial function, as measured by the rate of left ventricular pressure increase at 40 mmHg, the rate of left ventricular decline, cardiac index, and duration of survival, was significantly improved in both preconditioned and K(ATP) channel opener-treated animals. K(ATP) channel blocker administered 45 min before induction of ischemic preconditioning completely abolished the myocardial protective effects of preconditioning. We conclude that ischemic preconditioning significantly improved post-CPR myocardial function and survival. These results also provide evidence that the myocardial protective effects of ischemic preconditioning are mediated by K(ATP) channel activation.

Periodicity of arrhythmias in healthy elderly men at the moderate altitude.

The 24-hour periodicity of supraventricular (SVPB) and ventricular (VEB) extrasystoles in healthy elderly men (age 49-69 years) was studied at two altitudes during 24 h Holter ECG monitoring. At the low altitude (200 m, n = 26), SVPB were more frequent than VEB. The highest occurrence of SVPB was at 17:00 h, the lowest at 01:00 and 02:00 h (P<0.001). The highest occurrence of VEB was at 09:00 h, the lowest one at 04:00 h (P<0.001). At 1350 m (n=9) the incidence of both SVPB and VEB was approximately twofold higher compared to that at the low altitude (P<0.001). The highest occurrence of SVPB was at 13:00 h, the lowest at 06:00 h (P<0.001). VEB were the most frequent at 10:00 h and 13:00 h, while the lowest frequency was observed at 06:00 h (P<0.001). Our results indicate that the incidence of SVPB and VEB in healthy persons at the moderate altitude is twofold and its periodicity is shifted compared to the low altitude. The cause of increased occurrence of extrasystoles is probably due to beta-adrenergic activation of the heart at the higher altitude.

Results of Holter monitoring U.S. Air Force aircrew with ectopy on 12-lead electrocardiograms.

PURPOSE: To evaluate the results of 24-h Holter monitoring performed on healthy U.S. Air Force aircrew with asymptomatic ectopy on resting electrocardiograms (ECG). METHODS: A historical review of the USAF Central ECG Library database was conducted on all Holter studies completed for evaluation of ECG ectopy between 1 Jan 86 and 31 Dec 97. Univariate and multivariate statistical analyses were performed to determine the association between ectopy and the aeromedical dispositions of aircrew evaluated for incidental ECG ectopy. RESULTS: During this period, 147,571 resting ECGs were submitted to the Aeromedical Consultation Service (ACS) for interpretation. The mean age of the subjects was 35 yr (range 19 to 57 yr). There were 480 24-h Holter studies performed for ECG ectopy. Of these, 49% had normal or normal variant findings; another 11% were found acceptable for flying after normal treadmill testing and echocardiography. ACS evaluation was required for the remaining 40% of subjects. Overall, 4% were permanently disqualified, and 17% were lost to follow-up. Excluding subjects lost to follow-up, 95% of aircrew were returned to flying status (with or without a waiver). CONCLUSIONS: When controlled for age, no significant difference of aeromedical outcome was seen when comparing supraventricular and ventricular ectopy. Of the subjects, 51% had abnormal Holter studies, but the vast majority were returned to flying. Results of this study provide information useful in further defining aircrew medical evaluation protocols for evaluation of asymptomatic ECG ectopy with Holter monitoring.

Cardiac dysrhythmias induced by extracorporeal shockwave lithotripsy.

PATIENTS AND METHODS: We evaluated in 269 consecutive patients the incidence and gravity of dysrhythmic complications during nonsynchronized extracorporeal shockwave lithotripsy (SWL) using an electromagnetic lithotripter. RESULTS: Dysrhythmia occurred during treatment in 22 patients (8.8%) with no previous cardiac dysrhythmia. Ventricular extrasystoles occurred in 14 patients, atrial extrasystoles in 7 patients, and sinus bradycardia in 1 patient. It was not necessary to terminate treatment because of the occurrence of dysrhythmia in any of the patients. For 13 of the 22 patients (59%), it was sufficient to interrupt the treatment momentarily to obtain resumption of the normal rhythm. For 8 patients (36%), treatment was continued after triggering the release of the shockwaves with the refractory phase of the heart cycle. For one case of bradycardia (42 beats/min), it was possible to continue with the treatment after intravenous administration of atropine 0.5 mg. Pretreatment dysrhythmias were revealed by the electrocardiographic examination in 16 of the patients studied (6.3%). CONCLUSIONS: Extracorporeal shockwave lithotripsy without ECG triggering has been found to be fast and efficient and not correlated with the occurrence of dysrhythmic episodes of any particular clinical significance. No significant correlation was found between the occurrence of dysrhythmia, the side treated, the number and strength of the shockwaves, or the administration of analgesics. It was found, however, that dysrhythmia occurred almost exclusively in treatments involving the kidneys. The ECG-triggering option was indispensable in some patients in order to complete the lithotripsy without complications.

Trandolapril decreases prevalence of ventricular ectopic activity in middle-aged SHR.

BACKGROUND: Although severe arrhythmias are still a major problem in patients with left ventricular hypertrophy (LVH), the relationship between ventricular remodeling and its regression or prevention, and the prevalence of ventricular premature beats (VPB) or more sustained arrhythmias are still poorly explored in hypertensive heart disease. METHODS AND RESULTS: Holter monitoring was used to quantify supraventricular premature beats and VPB and heart rate (HR) in middle-aged spontaneously hypertensive rats (SHR) and Wistar rats treated for 3 months with trandolapril (ACE inhibitor, 0.3 mg/kg per day). Hypertrophy and fibrosis were morphometrically determined. Statistical analysis was performed with the use of simple regression and multivariate data analysis (cluster and correspondence analysis). SHR have higher cardiac mass and fibrosis, more VPB, and a decreased HR. Cluster analysis demonstrated that trandolapril was only effective in SHR. Trandolapril significantly reduced cardiac hypertrophy, fibrosis, and VPB incidence and increased the HR. Simple regression analysis showed that VPB incidence correlated to both hypertrophy and fibrosis. Correspondence analysis evidenced a strong correlation between hypertrophy, fibrosis, and VPB, but only for severe hypertrophy, and the correlation disappeared for moderate hypertrophy. CONCLUSIONS: After trandolapril treatment, the regression of VPB incidence not only is linked to hypertrophy and fibrosis, but additional causal factors also are involved including the myocardial phenotype and new calcium metabolism. Our model of Holter monitoring in conscious middle-aged SHR and multivariate data analysis might be useful in correlating myocardial structural modifications and ectopic activity.

Depression and 18-month prognosis after myocardial infarction.

BACKGROUND: We previously reported that major depression in patients in the hospital after a myocardial infarction (MI) substantially increases the risk of mortality during the first 6 months. We examined the impact of depression over 18 months and present additional evidence concerning potential mechanisms linking depression and mortality. METHODS AND RESULTS: Two-hundred twenty-two patients responded to a modified version of the National Institute of Mental Health Diagnostic Interview Schedule (DIS) for a major depressive episode at approximately 7 days after MI. The Beck Depression Inventory (BDI), which measures depressive symptomatology, was also completed by 218 of the patients. All patients and/or families were contacted at 18 months to determine survival status. Thirty-five patients met the modified DIS criteria for major in-hospital depression after the MI. Sixty-eight had BDI scores > or = 10, indicative of mild to moderate symptoms of depression. There were 21 deaths during the follow-up period, including 19 from cardiac causes. Seven of these deaths occurred among patients who met DIS criteria for depression, and 12 occurred among patients with elevated BDI scores. Multiple logistic regression analyses showed that both the DIS (odds ratio, 3.64; 95% confidence interval [CI], 1.32 to 10.05; P = .012) and elevated BDI scores (odds ratio, 7.82; 95% CI, 2.42 to 25.26; P = .0002) were significantly related to 18-month cardiac mortality. After we controlled for the other significant multivariate predictors of mortality in the data set (previous MI, Killip class, premature ventricular contractions [PVCs] of > or = 10 per hour), the impact of the BDI score remained significant (adjusted odds ratio, 6.64; 95% CI, 1.76 to 25.09; P = .0026). In addition, the interaction of PVCs and BDI score marginally improved the model (P = .094). The interaction showed that deaths were concentrated among depressed patients with PVCs of > or = 10 per hour (odds ratio, 29.1; 95% CI, 6.97 to 122.07; P < .00001). CONCLUSIONS: Depression while in the hospital after an MI is a significant predictor of 18-month post-MI cardiac mortality. Depression also significantly improves a risk-stratification model based on traditional post-MI risks, including previous MI, Killip class, and PVCs. Furthermore, the risk associated with depression is greatest among patients with > or = 10 PVCs per hour. This result is compatible with the literature suggesting an arrhythmic mechanism as the link between psychological factors and sudden cardiac death and underscores the importance of developing screening and treatment programs for post-MI depression.

Variability of the ventricular response in atrial fibrillation and prognosis in chronic nonischemic mitral regurgitation.

Although reduced heart rate (HR) variability during sinus rhythm is associated with an adverse prognosis in a variety of clinical settings, the significance of measures of variability of the ventricular response in atrial fibrillation (AF) requires clarification. AF is common among patients with chronic severe mitral regurgitation (MR) and potentially limits the application of HR variability techniques in this population. Therefore, this study examined the physiologic correlates and prognostic significance of measures of HR variability in 21 patients with nonischemic causes of chronic severe MR who had chronic AF and underwent 24-hour ambulatory electrocardiography as part of a prospective study of the natural history of regurgitant valvular heart disease. Patients were followed for up to 9.1 years and end points of mortality and progression to mitral valve surgery were tabulated. Time- and frequency-domain measurements of high-, low-, and ultra-low-frequency HR variability were computed and compared with resting ventricular function by radionuclide cineangiography and outcome. All measures of HR variability were covariate (pair-wise r values between 0.48 and 0.99, all p values < 0.03), and none of the variables was significantly related to age, ventricular premature complex (VPC) density, or right or left ventricular ejection fraction. Reductions in time-domain measurements of ultra-low- and high-frequency HR variability were significant predictors of the combined risk of mortality or requirement for mitral valve surgery (p = 0.02 and p = 0.05, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Usefulness of Holter monitoring in predicting efficacy of amiodarone therapy for sustained ventricular tachycardia associated with coronary artery disease.

The ability of Holter monitoring to predict clinical events during amiodarone therapy was evaluated in 83 patients with coronary artery disease and inducible monomorphic ventricular tachycardia. Sixty-four patients (77%) had significant ventricular ectopy activity (> or = 10 ventricular premature complexes [VPCs]/hour) at baseline, and 19 (23%) did not; patients were similar in age (63 and 65 years, respectively; p = 0.24) and ejection fraction (31 and 32%, respectively; p = 0.75). Over a mean of 23 +/- 17 months, there was no difference in arrhythmia recurrence (33 and 26%; p = 0.89) or sudden death (16 and 20%; p = 0.94) in patients with and without significant ectopy, respectively. In patients with significant ectopy, amiodarone decreased VPC frequency from baseline to 2 weeks, but not from 2 to 6 weeks. Forty-two patients had > 85% reduction in ectopy at 2 weeks; 20 patients did not. However, this reduction of simple VPCs did not predict a decrease in arrhythmic recurrence (29 vs 40%; p = 0.59) nor sudden death (25 vs 11%; p = 0.56) in patients with and without VPC suppression, respectively. Forty-five patients had Holter monitoring at 6 weeks. Twenty-one patients (47%) had > 95% suppression of ectopy, and 24 did not. Neither the recurrence (38 vs 38%; p = 0.54) nor sudden death (33 vs 13%; p = 0.45) rate was predicted by the degree of VPC suppression. Amiodarone is a powerful suppressant of VPCs, but Holter suppression of this ectopic activity is not predictive of clinical outcome.

Frequency of predischarge ventricular arrhythmias in postmyocardial infarction patients depends on residual left ventricular pump performance and is independent of the occurrence of acute reperfusion. The GISSI-2 Investigators.

OBJECTIVES: To test whether acute reperfusion of the infarct-related vessel after an acute myocardial infarction is associated with a subsequent reduction in spontaneous ventricular arrhythmias that is independent of ventricular ejection fraction, 1,944 patients from the GISSI-2 study population were studied. The patients were selected on the basis of a first myocardial infarction and the availability of two-dimensional echocardiographic ejection fraction and data on the number of premature ventricular contractions per hour on Holter monitoring. BACKGROUND: It has been suggested that postthrombolytic reperfusion of the culprit vessel may be associated with an increased electrical stability of the infarcted heart, irrespective of its residual pump performance. METHODS: The predischarge relation between ejection fraction and number of premature ventricular contractions per hour was plotted according to the occurrence (1,309 patients) or not (635 patients) of acute reperfusion, identified noninvasively according to the modifications of the ST segment in serial electrocardiograms obtained in the first 24 h after infarction. RESULTS: The frequency of premature ventricular contractions increased in a linear fashion with decreasing ejection fraction in both cohorts (p < 0.005 and p < 0.0001); however, there was no significant difference between the slopes and the intercepts of the two regression lines, so that the relation between ejection fraction and number of premature ventricular contractions per hour could be adequately described by a single equation: y (number of premature ventricular contractions) = 33.0-0.42x (ejection fraction) (r = -0.107, p < 0.0001). The results were the same even when differences between group characteristics were accounted for in a multiple regression model. CONCLUSIONS: It is concluded that 1) the number of premature ventricular contractions per hour after an acute myocardial infarction is dependent in a linear, inverse fashion on the residual ventricular ejection fraction, and 2) this relation is independent of the occurrence of reperfusion in the acute phase of infarction.

Correlates of ventricular ectopic activity in isolated systolic hypertension. SHEP Cooperative Research Group.

Ventricular ectopic activity was recorded at baseline in 5.6% of the 12-lead electrocardiograms and 8.2% of the 2-minute rhythm strips of 4674 subjects with isolated systolic hypertension (systolic blood pressure 160 to 219 mm Hg, diastolic blood pressure < 90 mm Hg) participating in the Systolic Hypertension in the Elderly Program (SHEP). In this study 1.3% had 6 to 10 ventricular premature beats (VPB), and 0.7% had > 10 VPB on the 2-minute rhythm strip. Correlates of VPB presence on the 12-lead ECG were older-age male sex, presence of Q/QS pattern and higher heart rate. Participants with serum potassium < 3.5 mmol/L had a higher prevalence of VPB. Similarly, the number of VPB on the 2-minute rhythm strip was associated with male sex, increasing age, with lower serum potassium, history of palpitations, and presence of Q/QS patterns.