bluuebunny/crossref_metadata_2025 huggingface dataset:
Sustained inotropic effects of a new cardiotonic agent. OPC‐8212 in patients with chronic heart failure
Authors: Asanoi H. , Sasayama S. , Kameyama T. , Ishizaka S. , Iuchi K.
Published: February 2009

OPC‐8212, a newly synthesized noncatecholamine, nonglycosidic, orally effective inotropic agent, has been shown to exert a potent cardiotonic action in acute administration to patients with heart failure. However, its long‐term effect has not yet been established. Eight patients with dilated cardiomyopathy (New York Heart Association functional class II—III) were given a single dose of 60 mg of OPC‐8212 daily for4 to 8 weeks. OPC‐8212 produced symptomatic improvement in four patients. Though there were no detectable changes in arterial pressure and left ventricular end‐diastolic dimension, heart rate and end‐systolic dimension significantly decreased after administration of OPC‐8212. Baseline fractional shortening rose significantly and depression of shortening in response to acute pressor stress (afterload mismatch) was corrected after OPC‐8212. The end‐systolic pressure‐dimension relation was shifted to the left with a steeper slope. These findings indicate that the inotropic state was substantially enhanced by the drug. No adverse effects were observed in any patient. Thus, the drug appears to hold promise for the chronic treatment of patients with moderate congestive heart failure who are essentially asymptomatic at rest, but develop severe impairment of cardiac function in a stressed state.
Acute myocardial infarction due to coronary spasm associated with l‐thyroxine therapy
Authors: Hiasa Y. , Ishida T. , Aihara T. , Bando M. , Nakai Y. , Kataoka Y. , Mori H.
Published: February 2009

A 63‐year‐old man with hypothyroidism is described. He had been receiving L‐thyroxine therapy following mitral valve surgery. About three weeks into the therapy regimen, he complained of severe retrosternal chest oppression. Electrocardiographic findings and laboratory data indicated a diagnosis of acute myocardial infarction due to the L‐thyroxine therapy. Emergency selective coronary angiography was performed. Comparing his coronary angiograms with those obtained before surgery indicated a severely spastic left coronary artery. We believe this is the first report of myocardial infarction due to coronary spasm, demonstrated by angiography associated with L‐thyroxine therapy.
Nicardipine, a new calcium channel blocker: Role for vascular selectivity
Authors: Pepine C.
Published: February 2009

Calcium channel blockers are important drugs for the treatment of chronic stable angina. However, negative inotropic and dromotropic effects may limit their usefulness in patients with atrioventricular conduction abnormalities or left ventricular dysfunction. A new generation of calcium channel blockers will soon be available that have a more vascular selective action than currently available agents. Of the new agents, nicardipine has been most extensively studied. In experimental studies, nicardipine is more specific for vascular smooth muscle than for cardiac smooth muscle and for coronary than peripheral vasculature. In controlled trials, nicardipine exhibited efficacy and safety that was comparable to older calcium blockers or beta blockers. However, nicardipine was associated with minimal negative inotropic or dromotropic effects even in patients with existing left ventricular dysfunction. Thus, nicardipine may have an advantage over existing calcium channel blockers, especially in patients with underlying cardiac disease.
Does ergometric stress test induce a procoagulative condition in patients with previous myocardial infarction?
Authors: De SCALZI M. , Deleonardis V. , Becucci A. , Lusini C. , Brardi L. , Cinelli P. , Rafanelli D. , Cinotti S. , Filimberti E. , Longo G.
Published: February 2009

A regularly scheduled physical training program seems to have antithrombotic effects. Moreover, the hemostatic changes occurring in patients with coronary artery disease during acute exercise have not been clearly elucidated. Since stress testing is routinely performed in clinical cardiology, it would be helpful to assess whether patients with coronary artery disease are exposed to acute coronary thrombosis during or soon after sustained physical exercise. This study was designed to evaluate the effect of acute physical exercise (stress test by bicycle ergometer) on blood coagulation in a group of patients with previous myocardial infarction, and to determine whether the antithrombotic therapy commonly administered favorably influences hemostatic equilibrium. Our results suggest that exercise testing is not harmful to patients with previous myocardial infarction in regard to hemostasis and fibrinolysis and that antithrombotic therapy reduces postexercise increase in platelets.
Peripheral percutaneous transluminal laser angioplasty in humans: In vitro investigations and clinical results with a novel laser catheter system
Authors: Neubaur T. , Klepzig M. , Heintzen M. P. , Richter E. I. , Zeitler E. , Strauer B. E.
Published: February 2009

Percutaneous transluminal laser angioplasty has become an accepted method of treatment of peripheral arterial occlusive disease. To minimize the risk of arterial wall perforation during laser angioplasty, a novel laser catheter system was developed. in 113 obliterated postmortem human arteries the perforation rate was 0.9%. The mean degree of stenosis was reduced from 89±9% before, to 53±11% after laser irradiation. Clinical Nd:YAG laser angioplasty was performed in 19 patients suffering from peripheral arterial occlusive disease. The Fontaine stage improved in 16 patients; in no case did it deteriorate. The mean degree of stenosis was reduced by laser angioplasty from 91±12% to 31±19%. A further reduction down to 13±18% was achieved by subsequent percutaneous transluminal balloon angioplasty. The systolic Doppler ankle‐arm pressure gradient was improved from 0.58±0.26 to 0.89±0.25. in 7 patients microembolisms were detectable on the final angiogram. There was no acute reocclusion and no perforation. Within a follow‐up period of 12 months, four restenoses were diagnosed by digital subtraction angiography. On average, the Doppler index was 0.75±0.32.
Runaway pacemaker: A still existing complication and therapeutic guidelines
Authors: Mickley H. , Andersen C. , Hedemann Nielsen L.
Published: February 2009

Runaway pacemaker is a rare, but still existing potential lethal complication in permanent pacemakers. Within 4 1/2 years, we saw two cases of runaway pacemaker in patients with multiprogrammable, VVI pacemakers (Siemens‐Elema, Model 668). In both cases a pacemaker‐induced ventricular tachycardia (rate 240–260 beats/min) was documented. One patient died. Runaway pacemakers must be exchanged as soon as possible. Until this can be accomplished, different emergency maneuvers should be tried. As documented in the cases presented, placing a magnet over the pacemaker may result in a lower, more physiological pacing rate. Reprogramming the pulse generator to a lower output or the use of external chest wall overdrive stimulation may also be successful, but these procedures require the presence of an adequate escape rhythm. If this is not the case or the former maneuvers have failed, an external pacemaker may be connected to the permanent pacing lead. Thereafter, the lead can be safely cut. As an alternative, a temporary transvenous pacing lead may be established prior to disconnecting the permanent pacing lead.
Implantable electrical devices in the management of tachyarrhythmias
Authors: De Belder M. A. , Camm A. J.
Published: February 2009

Electrical therapy for tachyarrhythmias attempts to achieve one or more of three aims: a) prevention of tachycardia; (b) control of the hemodynamic effect of tachycardia; (c) termination of tachycardia. In practice, long term control of tachycardia in selected patients can be achieved with implantable devices which can automatically recognize and terminate tachycardias. Termination can be achieved with a number of pacing modalities. These pacing modalities are reviewed in this article and some guidelines to the choice of modality are given. Patients with supraventricular tachycardia are often more appropriately treated with drugs or surgery but some can be effectively treated with antitachycardia pacing. Some patients with ventricular tachycardia can be successfully treated with these devices but this group is at risk of tachycardia acceleration or degeneration in response to pacing. An implantable cardioverter‐defibrillator should be used as a backup in these patients. Present generation devices now incorporate antitachycardia pacing, low energy cardioversion, and higher energy defibrillation in the same unit.
Prediction of arrhythmic events in patients following myocardial infarction
Authors: Cripps T. R. , Camm A. J.
Published: February 2009

The value of techniques used to predict arrhythmic events (sudden cardiac death not preceded by reinfarction and spontaneous sustained ventricular tachycardia) after acute myocardial infarction is reviewed. A full clinical assessment allows the detection of patients with major infarction, present in the majority of those suffering arrhythmic events during follow‐up. More sophisticated noninvasive tests, including Holter monitoring, and the high gain, signal averaged ECG, add prognostic accuracy to clinical assessment in patients with major infarction but are by themselves nonspecific. Noninvasive assessment of autonomic function from baroreceptor sensitivity analysis and heart rate variability measurement may also provide useful prognostic information. The results of programmed ventricular stimulation studies in patients with recent acute infarction have been contradictory, though many of the disagreements can be explained by methodological differences. At best this technique is highly invasive, and probably adds little to what can be discovered from a thorough noninvasive assessment. The treatment to be adopted in those judged to be at high risk remains to be established, and this may include nonpharmacological modalities such as the implantable defibrillator and surgical ablation as alternatives to drug therapy.
Long‐Term prognosis in children with hypertrophic cardiomyopathy: An analysis of 37 patients aged ≤ 14 years at diagnosis
Authors: Romeo F. , Cianfrocca C. , Pelliccia F. , Colloridi V. , Cristofani R. , Reale A.
Published: February 2009

The relation of clinical, electrocardiographic, and hemodynamic findings at diagnosis to presenting features and prognosis of hypertrophic cardiomyopathy in childhood was evaluated in 37 consecutive patients below 14 years of age at time of diagnosis (24 males and 13 females, mean age 7 ± 4 years). A left ventricular outflow tract gradient (mean 42 ± 27 mmHg) was detected at cardiac catheterization in 13 (35%) patients. Clinical, electrocardiographic, and hemodynamic features in patients with and without a pressure gradient were similar. Patients who had moderate to severe functional limitation had a higher incidence of syncopal episodes (p < 0.001), lower ejection fraction (p < 0.01), raised pulmonary artery pressure (p < 0.001), and left ventricular end‐diastolic pressure (p < 0.01). During a follow‐up of 9.2 ± 5.1 years (range 2‐18), 9 (24%) patients died suddenly (2 with a recorded left ventricular outflow tract gradient). Univariate analysis showed that reduced ejection fraction (p=0.0001), syncopal episodes (p=0.003), increased left ventricular end‐diastolic pressure (p=0.03), and severe dyspnea (p=0.04) were associated with a poor prognosis. However, multivariate analysis revealed ejection fraction (p=0.0001) and syncopal episodes (p=0.0097) as independent predictors of survival. In conclusion, sudden cardiac death was common and was well predicted by the combination of left ventricular dysfunction and syncope at time of diagnosis.
Aspirin and dipyridamole and their limitations in the therapy of coronary artery disease
Authors: Rowe G. G. , Folts J. D.
Published: February 2009

We have reviewed some of the voluminous literature on the effects of aspirin combined with dipyridamole on coronary thrombosis. There is clear evidence that aspirin is partially effective in preventing platelet aggregation and subsequent thrombosis in experimental constricted and damaged coronary arteries of dogs. Clinical studies show a clear reduction in myocardial infarction in male human subjects who are given aspirin as therapy for unstable angina, or as prophylaxis in asymptomatic individuals. In many studies aspirin and dipyridamole have been combined and are effective. We have not found dipyridamole to be effective in the dog with coronary artery constriction and find no substantial evidence that it is effective in preventing myocardial infarction in man. Until definitive studies show that combining dipyridamole with aspirin is more effective than aspirin alone, we do not recommend its use for prevention of coronary thrombosis.
Reperfusion injury
Authors: Fishbein M. C.
Published: February 2009

This article reviews the early and late morphologic changes associated with reperfusion of ischemic myocardium. If instituted within minutes of coronary artery occlusion, all reversibly injured myocardium is salvaged. Once some irreversibly injured myocardium is present, the usually bland region of coagulation necrosis is transformed into an edematous, hemorrhagic zone with “contraction‐band” necrosis and vascular obstruction (no‐reflow phenomenon). Whether or not these changes occur in otherwise salvageable myocardium is controversial. Data from studies with conflicting results are presented. Popular proposed mechanisms of reperfusion injury include the no‐reflow phenomenon and free radical‐mediated injury. No reflow has been related to direct vascular injury, compression of capillaries by edema fluid, and obstruction of vascular channels by leukocytes. Free radicals, which inactivate enzymes and destroy membranes, are primarily oxygen derived, and produced by neutrophils, endothelial cells, and myocardial cells. Whether or not reperfusion injury exists is still debated; if it does, the mechanism of injury remains to be proven. Ongoing research in this field will augment our knowledge of cell death and interventions to delay or prevent it.
Mexiletine: Pharmacology and therapeutic use
Authors: Manolis A. S. , Deering T. F. , Cameron J. , Markestes N. A.
Published: February 2009

Mexiletine is a Class IB antiarrhythmic which has basic and clinical electrophysiologic properties similar to lidocaine. Like other Class I antiarrhythmic agents, mexiletine blocks the rapid inward sodium current responsible for phase 0 of the action potential. It has been noted in the clinical electrophysiology laboratory to have minimal effect on sinus node function and AV nodal and His‐Purkinje system conduction. Pharmacokinetic studies have shown that oral absorption is rapid with bioavailability of 80‐90%. Mexiletine is predominantly metabolized by the liver with elimination half‐life of 9 to 12 hours. The antiarrhythmic effects of the primary drug's metabolites remain to be defined. Hemodynamic studies have shown mexiletine to have a lesser negative inotropic effect than procainamide or disopyramide. Although mexiletine as a single agent successfully suppresses 60 to 80% of spontaneous ventricular arrhythmias, it has lower efficacy in suppression of induced ventricular arrhythmias. Multiple studies have shown that as monotherapy mexiletine is effective in preventing the induction of ventricular tachycardia in approximately 20% of patients. When used in combination with a Class IA antiarrhythmic drug for suppression of induced ventricular arrhythmias, multiple investigators have reported greater efficacy. Neurological side effects (tremor, dizziness, memory loss) occur in approximately 10% of patients while gastrointestinal side effects (nausea, anorexia, gastric irritation) occur in up to 40% of patients. Proarrhythmia or other serious toxicity from the drug is uncommon.
An update to silent myocardial ischemia: Pathophysiological, diagnostic, and therapeutic approaches
Authors: Fu L. X. , Hjalmarson Å.
Published: February 2009

Silent myocardial ischemia (SMI) is a common ischemic process which can be defined as objective evidence of myocardial ischemia without chest pain or other equivalent indications. SMI can occur in totally asymptomatic patients, as well as in patients who have documented coronary artery disease (CAD) and who, on exercise and/or during Holter monitoring, may show ischemic changes. The precise mechanism for pathogenesis and pathophysiology of SMI remains to be clarified. A great deal has been learned about the role of beta‐adrenergic receptors, adenylyl cyclase, and guanine nucleotide binding proteins (G proteins) in the myocardial ischemic process of SMI. Moreover, standard exercise test and long‐term ECG recordings have proved to be of great value, especially when performed jointly, however, in this field there is still room for expanded knowledge. Pharmacological interventions to date have demonstrated the beneficial effects of beta‐adrenergic receptor antagonists and/or calcium antagonists as contributing substantially to reducing both frequency and duration of SMI episodes. However, therapeutic options to improve the prognosis of SMI appear to be limited.
Metabolic equivalents (METS) in exercise testing, exercise prescription, and evaluation of functional capacity
Authors: Jetté M. , Sidney K. , Blümchen G.
Published: February 2009

One metabolic equivalent (MET) is defined as the amount of oxygen consumed while sitting at rest and is equal to 3.5 ml O2 per kg body weight x min. The MET concept represents a simple, practical, and easily understood procedure for expressing the energy cost of physical activities as a multiple of the resting metabolic rate. The energy cost of an activity can be determined by dividing the relative oxygen cost of the activity (ml O2/kg/min)x by 3.5. This article summarizes and presents energy expenditure values for numerous household and recreational activities in both METS and watts units. Also, the intensity levels (in METS) for selected exercise protocols are compared stage by stage. In spite of its limitations, the MET concept provides a convenient method to describe the functional capacity or exercise tolerance of an individual as determined from progressive exercise testing and to define a repertoire of physical activities in which a person may participate safely, without exceeding a prescribed intensity level.
Heart rate variability
Authors: Malik M. , Camm A. J.
Published: February 2009

Reduced heart rate variability carries an adverse prognosis in patients who have survived an acute myocardial infarction. This article reviews the physiology, technical problems of assessment, and clinical relevance of heart rate variability. The sympathovagal influence and the clinical assessment of heart rate variability are discussed. Methods measuring heart rate variability are classified into four groups, and the advantages and disadvantages of each group are described. Concentration is on risk stratification of postmyocardial infarction patients. The evidence suggests that heart rate variability is the single most important predictor of those patients who are at high risk of sudden death or serious ventricular arrhythmias.
Aneurysmal coronary sinus associated with severe valvular heart disease
Authors: Wong C. ‐K. , Lau C. ‐P. , Cheng C. ‐H. , Leung W. ‐H.
Published: February 2009

We report a case of aneurysmal coronary sinus complicating severe valvular disease with severe tricuspid regurgitation. Injection in the left superior vena cava outlines the aneurysmal coronary sinus with stasis of the contrast. As this anomaly carries special surgical implication in patients requiring open heart surgery, a correct preoperative diagnosis is mandatory.
Management of the patient following coronary thrombolysis
Authors: Massel D. , Gill J. B. , Cairns J. A.
Published: February 2009

Myocardial salvage can be maximized by the early institution of thrombolytic therapy and aspirin. Certain patients may benefit from the administration of intravenous heparin, beta blockers, or nitroglycerin. The routine use of percutaneous transluminal coronary angioplasty (PTCA) or calcium‐channel blockers does not appear to be warranted. Recurrent myocardial ischemia should be vigorously treated with medical therapy and there may be value in cardiac catheterization, followed by PTCA or bypass surgery, depending upon the extent of myocardium at risk and the underlying coronary anatomy. Long‐term morbidity and mortality may be reduced by instituting aspirin and beta blockers as well as by modifying risk factors. There is no evidence for the long‐term benefit from any calcium‐channel blocker. Oral anticoagulation may be warranted in those patients with a mural thrombus, congestive heart failure, or atrial fibrillation. ACE inhibitors may be of value in the presence of left ventricular dysfunction and certainly in the presence of symptomatic congestive heart failure. Antiarrhythmic therapy is generally indicated only for symptomatic or life‐threatening arrhythmias. Residual myocardial ischemia should be sought by exercise testing, and those patients with poor exercise tolerance generally warrant cardiac catheterization in consideration for revascularization.
Infective endocarditis in the 1980s: Experience at a heart hospital
Authors: Mansur A. J. , Grinberg M. , Bellotti G. , Jatene A. , Pileggi F.
Published: February 2009

Three hundred episodes of infective endocarditis (IE) in 287 patients were studied from October 1978 to August 1986. The patients were in the age range of 0.2–78 (mean 30.76±16.06) years; 185 (68%) occurred in male patients. The etiologic agents were: Streptococci viridans group (93), enterococci (21), streptococci D group, nonenterococci (19), other streptococci (14), Staphylococcus aureus (59), Staphylococcus epidermidis (14), gram‐negative bacteria (16), other gram‐positive bacteria (16), fungi (4). Etiologic agents were not isolated in 52 (negative cultures). Valvular heart diseases occurred in 231 episodes, congenital heart diseases in 37, other heart diseases in 6. Sixty‐nine occurred in patients with prosthetic heart valves. In 69 there was no previous heart disease. Surgical treatment was performed in 102 episodes (37 with prosthetic valve IE and 65 with native valve IE); 22 patients (21%) died, 12 with prosthetic valve and 10 with native valve IE. The in‐hospital mortality (medical and surgical patients) was 26% (78 patients). Long‐term follow‐up of 206 patients up to 7.1 (mean 2.13±1.68) years revealed that 26 patients died. Thus, IE remains a disease with high mortality and is fatal to a third of the patients, in spite of the progress in therapeutic methods. Its morbidity and mortality continues beyond the microbiological cure.
Atrial natriuretic peptide response to ionic and nonionic contrast left ventriculography
Authors: Salvucci T. J. , Roman C. , Cha S. D. , Maranhao V.
Published: February 2009

Atrial natriuretic peptide (ANP) levels were measured prior to and at 1 and 5 minutes postcontrast left ventriculography with an ionic contrast agent (diatrizoate), and a nonionic agent (iopamidol) and the results were compared. Since ionic contrast agents have been found to cause an increase in left ventricular end‐diastolic pressure (LVEDP) and nonionic agents have been found to have less of an effect on LVEDP, we investigated the response of ANP levels, which have been found to increase secondary to increased LVEDP (atrial pressure), with both agents. A group of 38 patients who were scheduled for left heart catheterization for suspected coronary artery disease was included (19 in each group) and blood samples for ANP levels were drawn from the left ventricle. At the same time, heart rate, LVEDP, and left ventricular systolic pressure (LVSP) were also measured. It was found that the LVEDP increased significantly for both agents at 1 minute postventriculography, but no further change occurred at 5 min. Heart rate increased significantly in the diatrizoate group at 1 minute with a return of heart rate to preventriculography levels at 5 min, while the ANP level and LVSP remained unchanged at 1 minute postventriculography with both agents but increased significantly at 5 min in the diatrizoate group only. This difference in ANP response is not correlated with the LVEDP. The response of ANP may be related to heart rate and/or LVSP.
Alpha‐adrenergic blockers: Mechanism of action, blood pressure control, and effects on lipoprotein metabolism
Authors: Nash D. T.
Published: February 2009

The sympathetic nervous system plays a major role in the pathogenesis of essential hypertension and is mediated by the α and β receptors. The α receptor is divided into two types, α1 and α2 based on response to epinephrine and norepinephrine. α1‐Adrenergic receptors have a high affinity for drugs such as prazosin, doxazosin, and terazosin, which act to reduce blood pressure by selective blockade of the receptor. These agents provide a rational approach to the treatment of hypertension by correcting elevated total peripheral resistance, the fundamental hemodynamic abnormality in essential hypertension. In contrast, early α‐adrenergic receptor blockers nonselectively blocked both α1 and α2 receptors and were unsuitable as antihypertensive agents because they induced tachycardia and patients developed a tolerance to them rapidly. α1‐Adrenergic blockers also have beneficial effects on plasma lipoproteins, tending to decrease levels of triglycerides and cholesterol and increase levels of high‐density lipoprotein (HDL) cholesterol and the HDL cholesterol/total cholesterol ratio. β‐Adrenergic blockers, such as propranolol and atenolol, have been shown to have an adverse effect on the lipid profile by tending to increase levels of triglycerides and decrease HDL cholesterol. A number of mechanisms contribute to these effects, in particular, adrenergic modulation of lipoprotein lipase and the triglyceride secretion rate. Doxazosin has been shown to increase the activity of LDL receptors, which may be partly responsible for its beneficial effect on plasma lipids and lipoproteins. Doxazosin is different from other α1 adrenergic inhibitors in that its maximal hypotensive effect occurs within 5 or 6 hours after administration in acute dosing studies, making first‐dose postural hypotension unlikely, and its long half‐life provides 24‐h blood pressure control with once‐daily dosing.
Automatic junctional tachycardia in an adult
Authors: Kumagai K. , Yamato H. , Yamanouchi Y. , Matsuo K. , Tashiro N. , Hiroki T. , Arakawa K.
Published: February 2009

We report an adult patient with junctional ectopic tachycardia, a condition which was initially described in infants, frequently in association with congenital defects. The patient had a rapid, irregular paroxysmal junctional tachycardia with a rate ranging from 160 to 220 beats/min, distinguishing it from the more common nonparoxysmal junctional tachycardia in which a slower heart rate is seen. The electrophysiological study performed during an episode of tachycardia demonstrated periods of atrioventricular dissociation and narrow QRS complexes as well as a junctional ectopic rhythm, which was suggested by a His deflection preceding each ventricular depolarization with a normal HV interval. Both the response to exercise and the results of atrial and ventricular stimulation suggested enhanced automaticity of a high junctional focus. Therapy combining procainamide, verapamil, and digitalis proved to be effective. Thus, junctional ectopic tachycardia can also occur in adults, probably due to enhancement of automaticity.
Limitations of coronary angiography: An underestimated problem?
Authors: Katritsis D. , Webb‐Peploe M.
Published: February 2009

Angiographic imaging suffers from many limitations which may distort the diagnostic information obtained from coronary arteriograms. Radiographic features limiting precise coronary stenosis measurement are caused by the x‐ray source, the image intensifier, and the chemical properties of the cinefilm. Biologic variations are introduced by fluctuations in angiographic contrast concentration and flow‐ or contrast‐dependent coronary dilation. Random errors are also introduced by the selection of the radiographic projection and frame to be analyzed and the digitization of cineangiograms. These limitations and their significance in distorting quantitative information obtained from coronary angiograms are discussed in this review.
Pirmenol: An antiarrhythmic drug with unique electrocardiographic features—a double‐blind placebo‐controlled comparison with quinidine
Authors: Salerno D. M. , Fifield J. , Farmer C. , Hodges M.
Published: February 2009

Previous reports have stated that pirmenol is a Class IA antiarrhythmic drug that prolongs the QT interval, but did not use computerized electrocardiography. We randomized 18 patients with frequent ventricular ectopic depolarizations to pirmenol (8 patients) or quinidine (10 patients). Pirmenol was effective and tolerated for suppression of arrhythmia in all 7 patients treated (1 patient withdrew for personal reasons) but quinidine was effective and tolerated for 4 weeks in only 5 of 10 patients (p<0.05). Using computerized 12‐lead electrocardiography, the mean change in PR interval from placebo to treatment was 5 ± 18 ms for quinidine and 5 ± 11 ms for pirmenol (p = NS). The mean change in QRS interval was 5 ± 14 ms for quinidine and 10 ± 5 ms for pirmenol (p = NS). The mean change in QT interval was 46 ± 30 ms for quinidine and 8 ± 9 ms for pirmenol (p<0.01) and the mean change in JT interval was 41 ± 36 ms for quinidine and –2 ± 10 ms for pirmenol (p<0.01). After the double‐blind phase, 4 quinidine patients had computerized electrocardiographic intervals measured on pirmenol; the above findings were confirmed. These electrocardiographic features of pirmenol clearly distinguish it from quinidine, the prototype Class IA drug. However, pirmenol has minimal effect on the PR and QRS intervals, and thus does not appear to be a Class IC drug either. Although its electrocardiographic features are closest to Class IB, its electrophysiology in isolated cells and its antiarrhythmic and side effect profile are atypical for a IB agent. Pirmenol is a unique antiarrhythmic drug that merits further study. Results of this study suggest that the IA‐IB‐IC antiarrhythmic drug classification may be an over‐simplification.
Once‐daily pravastatin in patients with primary hypercholesterolemia: A dose‐response study
Authors: Jones P. H. , Farmer J. A. , Cressman M. D. , Mckenney J. M. , Wright J. T. , Proctor J. D. , Berkson D. M. , Farnham D. J. , Wolfson P. M. , Colfer H. T. , Rackley C. E. , Sigmund W. R. , Schlant R. C. , Arensberg D. , Mcgovern M. E.
Published: February 2009

This multicenter, double‐blind, placebo‐controlled study was conducted to evaluate dose‐response effects and safety of once‐daily administration of pravastatin, a new inhibitor of 3‐hydroxy‐3‐methylglutaryl coenzyme A (HMG‐CoA) reductase. Pravastatin 5, 10, 20, 40 mg or placebo was administered at bedtime to 150 patients with primary hypercholesterolemia inadequately controlled on a low‐fat, low‐cholesterol (AHA Phase I) diet. After 8 weeks of treatment, pravastatin produced dose‐dependent reductions in low‐density lipoprotein (LDL) cholesterol of 19.2 to 34.1% (p⩽.001 vs. baseline and placebo) and reductions in total cholesterol of 14.3 to 25.1% (p⩽.01 to p⩽.001 vs. placebo and p⩽.001 vs. baseline). The relationship between the loge dose of pravastatin and decrease in LDL cholesterol was linear (p<0.002). High‐density‐lipoprotein cholesterol increased up to 11.7% and triglycerides decreased by as much as 23.9%. Pravastatin was well tolerated; no patient withdrew from the study as a consequence of treatment‐related adverse events. Despite its relatively short serum half‐life of approximately 2 h, once‐daily administration of pravastatin provides a safe and effective means of reducing elevated LDL and total cholesterol.
Cardiac conduction defects associated with hyponatremia
Authors: Mouallem M. , Friedman E. , Shemesh Y. , Mayan H. , Pauzner R. , Farfel Z.
Published: February 2009

Cardiac conduction defects have not been previously described in association with hyponatremia, although in patients with congestive heart failure the frequency of ventricular premature beats was found to correlate to the severity of hyponatremia. We describe three patients with second‐degree or complete atrioventricular (AV) block which occurred during or shortly after an episode of severe hyponatremia. The first had thiazide‐induced hyponatremia while on amiodarone. In the second, definite etiology for hyponatremia which was associated with longstanding polydipsia could not be established. The third had ischemic heart disease and intermittent conversion of his first‐degree to second‐degree AV block while hyponatremic after diuretics use. Although it is usually difficult to single out hyponatremia as the cause of conduction defects which usually occur in the presence of cardiac disease, potent medications or other electrolyte abnormalities, we suggest that hyponatremia may play a role in the pathogenesis of conduction defects in the diseased heart.
Metastatic cardiac malignant fibrous histiocytoma presenting as right ventricular outflow tract obstruction
Authors: Kamlow F. J. , Padaria S. F. , Wainwright R. J.
Published: February 2009

An unusual case of metastatic disease of the right ventricle is described in a 74‐year‐old woman who had presented with a malignant fibrous histiocytoma of the right thigh previously treated with surgery and radiotherapy. Two years later she presented with signs and symptoms of tricuspid regurgitation and right ventricular outflow tract obstruction. The diagnosis of right ventricular tumor was made by echocardiographic and angiographic studies and confirmed on postmortem examination.
The relationship between exercise tolerance and quality of life in angina pectoris
Authors: Wiklund I. , Comerford M. B. , Dimenäs E.
Published: February 2009

The relationship between exercise tolerance assessed by a conventional exercise stress test using a standard Bruce protocol and quality of life (QoL) was studied in 50 patients with stable angina pectoris (AP). Before the exercise test, patients completed three self‐administered QoL questionnaires, the Psychological General Well‐Being Index, an Angina‐Specific QoL Questionnaire, and Jenkins' Sleep Dysfunction Scale. Total exercise time (r= ‐0.40) and time until onset of pain (r= ‐0.44) were significantly correlated with perceived physical limitations. Somatic symptoms were related to total time (r= ‐0.38). Apart from a significant correlation between depressed mood and total exercise time (r= 0.36), there was no corresponding correlation with well‐being and sleep disturbance. These results suggest that exercise stress tests do not reflect quality of life in patients with AP.
Hemodynamic, anti‐ischemic, and neurohumoral effects of slow‐release isosorbide‐5‐mononitrate in patients with coronary artery disease after short‐ and long‐term therapy
Authors: Mitrovic V. , Gessner C. , Hain P. , Müller K. D. , Schlepper M.
Published: February 2009

In 20 patients with established coronary artery disease, stable angina pectoris and reproducible ST‐segment depression, the pharmacokinetics and pharmacodynamic effects of 60 mg slow‐release isosorbide‐5‐mononitrate (IS‐5‐MN) (10 patients) after a 7‐day therapy were compared with those of a placebo group (10 patients) using a randomized double‐blind, placebo‐controlled study design. Ten patients could be controlled after long‐term therapy over a mean of 399 ± 111 days. There was no significant change under IS‐5‐MN of either blood pressure, heart rate, rate–pressure product, or myocardial oxygen consumption. Treatment over one week significantly reduced ST‐segment depression 4 and 8 h after drug intake (38–48% of the placebo value, p<0.01). Maximum reduction in ST‐segment depression was found 4 and 8 h after IS‐5‐MN intake both after one‐week and long‐term therapy at the time of peak plasma drug concentration (341 ± 95 and 405 ± 125 ng/ml, respectively). At a residual plasma concentration below 100 ng/ml, ST depression was not significantly improved 24 h after drug intake compared with placebo. Technetium‐99m ventriculography showed an insignificant increase in ejection fraction and a slight reduction of ventricular volumes after both short‐ and long‐term therapy with IS‐5‐MN (p>0.05). The drug's plasma levels were higher under chronic than under short‐term therapy which may be due to enzyme saturation. Maximum IS‐5‐MN plasma concentrations at a mean of 445 ± 116 ng/ml were reached after 5.8 ± 2.9 h. Beta‐phase half‐life of elimination was 9 ± 3 h. IS‐5‐MN administered as a single 60 mg dose of a slow‐release preparation/day proved to have a favorable pharmacokinetic profile as well as an efficient anti‐ischemic activity after both short‐ and long‐term therapy. Problems of tolerance or activation of hormonal counter‐regulation due to vasodilation were not observed.
Acute and chronic effects of nitrendipine in patients with precapillary pulmonary hypertension due to pulmonary fibrosis
Authors: Burger W. , Jandl M. , Kober G. , Schultze‐Werninghaus G. , Gellert J.
Published: February 2009

Eleven patients with histologically confirmed fibrosis of the lung were investigated for the effects of the dihydropyridine calcium antagonist nitrendipine on pulmonary hemodynamics. After 5 mg of acute sublingual nitrendipine, mean pulmonary artery pressure was significantly lowered (p≤0.05) from 32 ± 3 to 29 ± 3 mmHg at rest, and significantly lowered (p≤0.05) during exercise from 55 ± 4 to 49 ± 4 mmHg. Short‐term oxygen application at rest significantly reduced this parameter to 28 ± 3 mmHg(p≤0.01). Nitrendipine lowered total pulmonary vascular resistance during both rest (from 412 ± 50 to 351 ± 49 dyn•S•cm‐5; p≤0.05) and exercise (from 433 ± 61 to 383 ± 54 dyn•s•cm‐5; p≤0.05), although it did not affect pulmonary arteriolar resistance. Also, oxygen treatment at rest influenced only total pulmonary vascular resistance (reduction from 412 ± 50 to 373 ± 48 dyn•s•cm‐5; p≤0.01), but not pulmonary arteriolar resistance. Pressure‐flow curves, which were derived from cardiac output at rest and during exercise and from the corresponding gradient between mean pulmonary artery pressure and pulmonary capillary wedge pressure, remained unchanged by acute medication. Since a change in arterial oxygen partial pressure was not noticed after nitrendipine, arteriovenous shunting or a worsening of ventilation perfusion relationships can be excluded. Long‐term (3 weeks) treatment (double‐blind parallel design) with 10 mg of nitrendipine (4 patients) once daily showed no advantage in comparison to placebo (6 patients). From these observations we conclude that the reduction of lower circulatory pressures after nitrendipine is not caused by pulmonary arteriolar vasodilation, but rather by indirect effects due to the reduction of total peripheral resistance and left ventricular filling pressure.
Negative u wave during percutaneous transluminal coronary angioplasty
Authors: Yano Hayato , Hiasa Yoshikazu , Aihara Tsukasa , Nakaya Yutaka , Mori Hiroyoshi
Published: February 2009

To clarify the clinical significance of the negative U wave during acute myocardial ischemia, the appearance of the U wave and ST‐segment elevation on electrocardiography during percutaneous transluminal coronary angioplasty (PTCA) of the left anterior descending artery (LAD group: 11 patients) or right coronary artery (RCA group: 18 patients) was studied. During PTCA, U‐wave inversion (newly developed negative U wave, and increased negativity of the pre‐existing negative U wave) was observed in 37 (90%) of 41 patients in the LAD group and in 16 (89%) of 18 patients in the RCA group. The incidence of ST‐segment elevation was similar to that of U‐wave inversion; however, U‐wave inversion appeared before detectable ST‐segment elevation in 20 patients (49%) in the LAD group and in 4 patients (22%) in the RCA group. Moreover, U‐wave inversion was observed frequently in a wider range of leads than ST‐segment elevation. These results suggest that the U wave is a more sensitive indicator of myocardial ischemia than ST‐segment elevation in some patients, and that a negative U wave may be produced by a different mechanism than that which produces ST‐segment deviation, although both are related to myocardial ischemia.
Antithrombotic therapy in the coronary vein graft patient
Authors: Israel Douglas H. , Fuster Valentin , Stein Bernardo , Adams Philip C. , Stein Bernardo , Chesebro James H.
Published: February 2009

Coronary artery bypass grafting is an important therapeutic modality in the treatment of the patient with coronary artery disease; however, long‐term results are limited by the development of saphenous vein graft disease early and late after operation. The pathogenesis of early vein graft occlusion is primarily thrombotic, while that occurring later frequently involves thrombosis superimposed on intimal hyperplasia or vein graft atherosclerosis. We describe the role of various platelet inhibitors and anticoagulants in the prevention of saphenous vein graft occlusion following coronary artery bypass grafting.
Long‐term clinical course of patients with angina and angiographically normal coronary arteries
Authors: Voelker Wolfram , Euchner Ulrich , Dittmann Herbert , Karsch Karl R.
Published: February 2009

: In 88 of 103 consecutive patients with angina and normal coronary arteries, follow‐up data could be achieved 6–11 years (9.2 ± 1.2 years) after diagnostic left heart catheterization. Three of these patients died during follow‐up (two noncardiac deaths and one death with no identifiable etiology). One patient suffered a documented myocardial infarction. In 40 patients (47%) chest pain diminished, while symptoms were unchanged in 20 (24%) or even worse in 25 (29%). Resolution or persistence of chest pain could not be predicted either by the character of pain (typical vs. atypical), the presence of hypertension, a left bundle‐branch block, a positive exercise electrocardiogram or pathological pulmonary artery pressures during exercise, documentation of myocardial bridges, local wall motion abnormalities, or a left ventricular end‐diastolic pressure $$ 13 mmHg. However, continuing chest pain was significantly more common in patients who revealed a ‘slow‐flow phenomenon’ at initial coronary arteriogram.

Thus, in patients with angina and normal coronary arteries the long‐term course regarding frequency of morbid cardiac events is benign. However, more than half of the patients reported chest pain to be similar or even worse than at catheterization. Most clinical and invasive results at initial evaluation had no predictive value for the persistence of symptoms. The impact of ‘slow‐flow’ in coronary arteriography, which was a phenomenon almost exclusive to patients with constant or even worse chest pain at follow‐up, should be evaluated in larger patients populations.
Symptomatic bradycardia induced by the combination of oral diltiazem and beta blockers
Authors: Sagie Alex , Strasberg Boris , Kusnieck Jairo , Sclarovsky Samuel
Published: February 2009

Ten patients, who were admitted to the Intensive Coronary Care Unit during a one year period with symptomatic bradycardia while on combination therapy with oral diltiazem and beta‐blocker agents, are described. The important features of this adverse reaction to drug combination were that it appeared mainly in a relatively elderly age group and with presenting symptoms of lethargy, dizziness, syncope, chest pain, and (in one patient with poor left ventricular function) pulmonary edema. It was not dose dependent and occurred even in very low doses of each drug. Electrophysiologic abnormalities were localized to the sinus node in all 10 patients and the primary rhythm disorders were junctional escape rhythm, sinus bradycardia, and sinus pause. These rhythm abnormalities resolved within 24 h following withdrawal of the offending drugs. Temporary pacemaker insertion was necessary in four patients. The duration of drug combination used before the acute episode range from within hours to up to 2 years. In conclusion, although combination diltiazem/beta blocker therapy is very effective in ischemic syndrome, caution is advised when this combination is used especially in the elderly or in patients with left ventricular dysfunction or antecedent sinoatrial or atrioventricular conduction abnormality.
Conservative treatment of paroxysmal ventricular tachycardia during pregnancy
Authors: Chandra Nisha Chibber , Gates Elena A. , Thamer Mahmud
Published: February 2009

Paroxysmal ventricular tachycardia during pregnancy presents a therapeutic dilemma for the treating physician. The clinical course of two otherwise healthy pregnant patients with this arrhythmia in whom treatment was withheld is outlined. The indications and guidelines for treatment in relatively asymptomatic patients is discussed.
The S wave in acute anterior Q‐wave myocardial infarction: A study with serial multilead precordial maps and standard ECGs
Authors: Madias John E.
Published: February 2009

To investigate the relationship of S waves with R waves and/or Q waves in the ECGs of patients with acute myocardial infarction, 20 patients with anterior Q‐wave infarcts had serial 49‐lead precordial maps and simultaneously recorded standard ECGs on admission and at 13 predetermined time intervals, extending to their discharge from the hospital. The sums of S waves (ΣS) from ECG leads of both precordial maps and standard ECGs showing ST‐segment elevation on admission were correlated with the corresponding sums of R waves ($$R) and/or Q waves ($$Q). Correlation of $$S by the precordial maps and the $$S by the standard ECG was good (r=0.88). However, correlation of $$S with $$R and $$Q by both the precordial maps and standard ECG were poor (r values ranged between –0.02 and –0.32). Fair correlations were found between $$S + $$Q and the corresponding $$R by both ECG systems (r=–0.36, precordial map and r= –0.40, standard ECG). The present study demonstrates (1) that precordial (consequently partial) ECG mapping systems have no advantage over standard precordial ECG, and (2) that quantitative data from S waves correlate weakly with similar information from corresponding R waves or Q waves, but fairly with the latter two combined, as recorded by the two ECG systems employed.