Congenital dextrocardia complicated by hypertension,coronary artery disease and myocardial infarction

The case record of a seventy-three year old man with congenital dextrocardia and situs inversus viscerum complicated by hypertension, coronary artery disease and myocardial infarction is presented. Electrocardiographic recordings of the limb leads, with and without reversal of the arm lead wires, and of the precordial leads of the V series derived from both right and left chest areas are presented. In this instance the electrocardiographic findings in precordial leads taken over the right chest point to fresh anteroseptal infarction; those leads recorded from the left chest were not informative. This serves to emphasize the fact that precordial leads should be recorded from the right side of the chest rather than the left in order that the exploring precordial electrode may overlie the area of cardiac damage, and thus manifest maximal changes in the electrocardiogram. We agree that the electrocardiogram may best be interpreted by application of the usual criteria to the limb leads taken with the arm lead wires reversed although in this case the limb leads yielded no information of diagnostic significance.     

Spatial distribution of QT dispersion measured by magnetocardiography under stress in coronary artery disease.

This study investigated changes in spatial distribution of QT duration in patients with and without coronary artery disease (CAD) using magnetocardiography. Thirty-six-channel magnetocardiograms (MCGs) were registered at rest and under stress in 15 patients with chest pain, seven of whom had significant coronary stenosis. QT dispersion (QTd) was calculated for MCG and 12-lead electrocardiogram (ECG) under both conditions. For MCG, homogeneity of repolarization was measured using a smoothness index (SI). Also, at each registration site, the intraindividual difference between QT at rest and under stress was determined (deltaQT). QTd values as determined by standard 12-lead configurations were not significantly different between groups. MCG QTd values were significantly higher in the CAD group at rest only when all available channels were taken into consideration (P < .05); SI values differed significantly between groups under both conditions (rest, P < .005; stress, P < .01). Good separation between groups was possible using the range of deltaQT (P < .05) and SI (deltaQT) (P < .005). Consideration of the spatial distribution of QTd increases its sensitivity in the detection of CAD, suggesting that CAD involves complex changes in repolarization, not apparent in limited lead sets such as standard 12-lead configurations.     

Part I: abnormal patterns and physiological variations in magnetocardiograms.

Magnetocardiograms (MCGs) of six subjects with representative cardiac abnormalities and of one well-studied normal subject are compared with the 12-lead ECGs and VCGs of these subjects. The MCGs are recordings of the component of the magnetic vector which is normal to the skin, measured across the chest on a 5 cm X 5 am grid; an example is also presented of a sequence of instantaneous MCG maps. The heart abnormalities include myocardial infarction, angina pectoris, intraventricular conduction disturbances, and ventricular hypertrophy. The various MCG maps of the normal subject show MCG changes as a result of changes in body morphology (loss of weight), changes in the subject's position during recording, and changes as a result of exercise. They are presented as a basis for understanding some of the variability of MCG maps.     

The precordial lead in 104 normal adults

For the precordial lead the right arm electrode is placed on the anterior chest, just to the left of the sternum about the level of the apex, and the second electrode is on the left leg. The record is then taken as one usually derives Lead II of the standard electrocardiogram. This method is simpler than that of placing one electrode on the front and the other on the back of the chest.A simple glass electrode is described for obtaining precordial leads.It is suggested that the electrodes of the precordial lead be reversed so that P, R and T will be positive and only S inverted, just as they are in the standard electrocardiogram of normal adults.The precordial chest lead in 104 normal individuals is summarized. In this series the P-wave is shown to be negative, is not more than ?1.5 mm. and is usually followed by an end deflection above the isoelectric level. The P-Q interval averages 0.15 second. The QRS group is always diphasic, and never notched or slurred. Its duration is 0.09 second. The absence of the Q-wave or of the R-wave is definitely abnormal. The Q-wave averages ?5.3 mm. in size and the R-wave, +10.7 mm. No Q-wave less than ?1.5 mm. and no R-wave less than +2.5 mm. in size was ever observed. The R-T transition is below the isoelectric level, occasionally just isoelectric. A positive R-T transition or one that is more than 2 mm. below the isoelectric is definitely abnormal. The T-waves are always inverted and usually are less than ?6.0 mm. in size.The precordial lead may prove of service in interpreting which T-wave inversions of the third lead are abnormal.Left ventricular preponderance in the standard electrocardiogram of normal adults does not change the form of the precordial lead.     

Electrocardiographic Changes in Spontaneous Left Pneumothorax

ABSTRACT. Keller N, Szaff M, Sykulski R (Department of Internal Medicine, Sundby Hospital, Copenhagen, Denmark). Electrocardiographic changes in spontaneous left pneumothorax. Acta Med Scand 1987; 221:499–501. A 25-year-old man was admitted with severe chest pain and an electrocardiogram suggestive of anterior myocardial infarction. Echocardiogram was normal, but chest X-ray showed left-sided pneumothorax. The electrocardiogram showed increasing R-wave amplitude in the days after correction of pneumothorax. Taken in the supine position the electrocardiogram can be misleading in case of pneumothorax or mediastinal emphysema, but the electrocardiogram should be normal if taken in the erect position.     

Is exercise-induced U-wave inversion predictive of proximal left anterior descending coronary artery disease?

A 66-year-old patient with a recent history of chest pain was submitted to exercise test. The rest electrocardiogram was normal, but during effort, a striking U-wave inversion in the chest leads occurred, not associated with any ST-segment change. Coronary angiogram demonstrated a severe proximal narrowing of the left anterior descending coronary artery. Effort-induced U-wave inversion in the precordial leads has long been recognized as a marker of stenosis of the left anterior descending coronary artery, but this pattern is seldom taken into account.     

Isomagnetic maps in right ventricular overloading

Isomagnetic maps were recorded in normal subjects and in patients with systolic overloading of the right ventricle. The isomagnetic maps examined in this study indicated the instantaneous current source of the heart by applying the "corkscrew rule." The magnetic field recorded by a second derivative gradiometer detected clearly the cardiac current source from the right ventricle, which is located close to the anterior chest wall, and improved diagnostic sensitivity. Moreover, the isomagnetic map showed multiple dipoles, which are difficult to detect in the electrocardiogram or isopotential map. These results suggest that the magnetocardiogram provides useful information on current sources to supplement information obtained by the conventional electrocardiogram.     

The value of the electrocardiogram and chest X-ray for confirming or refuting a suspected diagnosis of heart failure in the community

BACKGROUND: There is a common assumption that a normal ECG or a normal heart size on chest X-ray virtually rules out a diagnosis of heart failure. AIMS: To assess the value of the electrocardiogram and chest X-ray in identifying patients with chronic heart failure in the community. METHODS AND RESULTS: This study was a secondary analysis of data prospectively collected at the time of patient's enrollment in the EPICA study, an epidemiological study of the prevalence of heart failure in Portugal. A total of 6300 subjects were clinically evaluated. Patients who presented with symptoms or signs of heart failure, and/or were receiving diuretics for chronic heart failure (CHF) had a chest X-ray, ECG, and echocardiogram. The diagnosis of heart failure was confirmed in 551 cases. Patients with right atrial enlargement, atrial flutter, atrial fibrillation, 2nd degree-Mobitz I atrioventricular block, 1st degree atrioventricular block, left bundle branch block, lung interstitial oedema, and bilateral pleural effusion were more likely to be diagnosed with heart failure. For the diagnosis of heart failure, in the Portuguese population aged over 25 years, an abnormal electrocardiogram had an estimated sensitivity of 81%, and negative predictive value of 75%; an abnormal chest X-ray had an estimated sensitivity of 57%, and negative predictive value of 83%. Twenty five percent of patients with CHF had a normal ECG or chest X-ray. CONCLUSION: Our results show that electrocardiographic and roentgenographic features are not sufficient to allow heart failure to be reliably predicted in the community and support the recommendation that all patients with suspected heart failure should undergo echocardiography.     

Unusual electrocardiographic changes during acute pancreatitis

A 46-year-old man suffered from mild upper abdominal pain radiating to the back and nausea; after a week he began to complain also of chest discomfort radiating to the neck and presented to the emergency room. A 12 leads electrocardiogram showed large peaked T waves in leads II-III-AVF and giant T waves inversion in AVL, V₁ through V₆; half an hour later the chest discomfort and the electrocardiographic changes resolved. Serum biochemistry results showed elevated serum pancreatic enzymes; electrolytes, creatinine kinase and troponin T serum values remained normal. Coronary angiography showed normal coronary arteries. The patient was conservatively managed.Electrocardiographic abnormalities were reported in patients with acute pancreatitis but broad, tall and peaked T waves, as found in our patient electrocardiogram, have not been yet reported.     

Magnetocardiography in coronary artery disease with a new system in an unshielded setting

BACKGROUND: The noninvasive detection of coronary artery disease (CAD) remains a clinical challenge. Magnetocardiography is a completely noninvasive method that permits the registration of cardiac electrical activity at multiple sites in a plane above the chest cage without the need for electrodes. In contrast to the electrocardiogram (ECG) which suffers from boundary effects and a variety of potential artifacts (electrode placement, etc.) the MCG is unaffected by such impediments as the magnetic field is unaltered by surrounding tissues. HYPOTHESIS: Magnetocardiography with a newly developed single-channel system in an unshielded setting should be a better qualitative diagnostic tool than the standard ECG for the detection and assessment of CAD. METHODS: In all, 52 patients with angiographically documented CAD and unimpaired ventricular function as well as 55 controls were included in this study. A standard 12-lead ECG was obtained in all subjects. The MCG recordings were taken from 36 positions under resting conditions. From these, current density vector maps were generated during the ST-T interval. Each map was then classified using a classification system with a scale from 0 (normal) to 4 (grossly abnormal). RESULTS: While the ECG was normal in all subjects, the MCG in the controls was classified as category 0, 1, or 2. However, in patients with abnormal coronary angiograms, mainly maps in categories 3 and 4 were seen (p < 0.05). CONCLUSION: A single-channel magnetometer in an unshielded setting reveals significant differences between normals and patients with CAD with normal ECG on the basis of current density reconstruction during the ST segment when measured under resting conditions. This method might be suitable for the noninvasive detection of CAD.     

Clinicopathological Conference(the 48th case)Adult gland pituitary hypofunction in an elderly female patient

Case presentation A female patient(a retired worker),68 years old,who complained mainly of "repeated episodes of dizziness,fatigue,vomiting in 6 years,chest tightness,chest pain for 1 year",was admitted to Heart Center,Chaoyang Hospital,Capital Medical University on February 24,2010.The patient suffered from dizziness and fatigue with unknown cause 6 years ago.She ever experienced sudden syncope and loss of conscioueness during visiting Xuanwu Hospital,when she presented with blood pressure of 62/? mmHg and slower heart rate,then her consciousness recoverd spontaneously 1-2 minutes later with no treatment.The head CT and electrocardiogram(ECG)showed no significant abnormality,and she was discharged after symptomatic treatment.Since then,the patient presented with intermittent anorexia,dizziness,nausea,vomiting,non-visual rotation,which were not affected by different body positions.All these symptoms appeared more frequently in winter,lasted for several days,relieved without any treatment.One year ago,the patient began to suffer from chest tightness and chest pain at physical activities.Each attack lasted for 3-5minutes and relieved by rest.In Xuanwu Hospital,the diagnosis of "coronary heart disease,angina pectoris " was established.After oral administration of "Wan Shuang Li" and other meidcations,chest tightness and chest pain appeared accidentally.Ten days ago,the patient experienced dizziness and vomiting(stomach contents,4-5 times a day on average).No visual rotation or tinnitus was accompanied.Twenty-nine hours before admission,the patient suffered from chest distress and chest pain again after 100 meters walking,accompanied with shoulder dispersion and sweating;the symptoms relieved after resting for 3-5 minutes.For further treatment,the patient visited Heart Center,Chaoyang Hospital.ECG showed "sinus bradycardia",and she was admittied for "arrhythmia".Since the onset,the patient displayed low blood pressure,slow heart rate,Susceptibility to coldness,frailty,poor appetite and sleep,normal stool.The body mass decreased by about 5kg over the past decade.     

Comparison of magnetocardiography and electrocardiography: a study of automatic measurement of dispersion of ventricular repolarization.

AIMS: There is some dispute over the clinical significance of dispersion of ventricular repolarization measurements from the electrocardiogram. Recent studies have indicated that multichannel magnetocardiograms (MCGs), which non-invasively measure cardiac magnetic field strength from many sites above the body surface, may provide independent information from ECGs about ventricular repolarization dispersion. For this study, magnetocardiography and electrocardiography were compared from automatic measurements of dispersion of ventricular repolarization. METHODS AND RESULTS: Dispersion of ventricular repolarization time was determined in MCGs and standard ECGs recorded simultaneously from 27 healthy volunteers and 22 cardiac patients. Two automatic techniques were used to determine the interval of ventricular repolarization. There were significant differences in ventricular dispersion between ECG and MCG measurements, with multichannel MCG greater than ECG by 52 (47) ms [mean (SD)] (P<0.00001) and 12-channel MCG greater by 17 (40) ms (P<0.004) across techniques and all subjects. Magnetocardiograms had the greater discriminating power between normal and cardiac patients with differences of 46 (18) ms (P<0.017) for multichannel MCG and 44 (16) ms (P<0.005) for 12-channel MCG, compared with 16 (7) ms (P<0.04) for ECG. CONCLUSION: Magnetocardiography has the power to discriminate regional cardiac conduction differences.     

Myocardial bridging of the left anterior descending artery: Evaluation using exercise thallium-201 myocardial scintigraphy

Seven patients with myocardial bridging of the left anterior descending coronary artery were evaluated by means of thallium-201 exercise scintigraphy. The degree of systolic narrowing was 60–70% in five patients and 75–80% in two patients. All patients had presented with chest pain. The resting electrocardiogram was normal in six patients; there were ST segment and T-wave abnormalities in one patient. No patient complained of chest pain during exercise. The exercise electrocardiogram was negative in six patients and inconclusive in one patient. Exercise myocardial scans were negative in all seven patients. We conclude that no evidence of ischemia was demonstrated in patients with myocardial bridging of the left anterior descending coronary artery as determined by exercise electrocardiography and stress thallium-201 scintigraphy.     

Efficient utilization of echocardiography for the assessment of left ventricular systolic function

BACKGROUND: We hypothesized that patients could be selected for echocardiographic evaluation of left ventricular (LV) systolic function on the basis of historic, clinical, radiographic, and electrocardiographic criteria. METHODS AND RESULTS: We prospectively evaluated 300 consecutive inpatients referred for the echocardiographic assessment of LV function, of whom 124 (41%) had LV systolic dysfunction (LVSD) (LV ejection fraction <0.45). Among the historic variables, male sex was the only predictor of LVSD, whereas of the abnormal physical and radiographic findings, cardiomegaly on chest radiography was the only predictor. Among the electrocardiographic findings, the presence of left bundle branch block was positively correlated with the presence of LVSD, whereas a normal electrocardiogram was negatively correlated with this finding. Only 2 patients with LVSD had a normal electrocardiogram. The addition of significant predictors on physical examination and chest radiography doubled the predictive value of the historic variables for determining LVSD. The addition of electrocardiographic findings further doubled the predictive value of the model. Almost 45% of the predictive power of the final multivariate model (chi-square of 48 of the total chi-square of 108) was based on the absence of normal electrocardiogram in patients with LVSD. When chest radiographic findings were excluded from the model, the overall predictive power of the model did not change, with the normal electrocardiogram gaining greater prominence: Full 56% of the predictive power of the model (chi-square of 60 of the total chi-square of 108) resided in the ability of a normal electrocardiogram to discriminate between patients with and those without LVSD. CONCLUSIONS: Historic, chest radiographic, and electrocardiographic variables can be used to predict low likelihood of LVSD on echocardiography. In particular, when the electrocardiogram is normal, it is extremely unlikely to have LVSD. It can be argued that such patients should not be referred for echocardiography.     

体位对心电图的影响

目的观察不同体位下心电图各波段振幅的改变,并分析体位对其影响。方法50例受检者均接受12导联动态心电图(Holter)及12导联电话传输远程心电图(TTM)记录,分别比较TTM和Holter在5种不同体位下的心电图各波段振幅。结果在II导联,体位对TTM和Holter各波段振幅造成的影响均无统计学意义;TTM的V1导联T波右侧卧位振幅较平卧位大(p=0.047),V5导联P波立位较平卧位高(p=0.044);Holter的V1导联S波左侧卧位较平卧位低(p=0.045),V5导联R波左侧卧位较平卧位高(p=0.04)。结论体位改变对TTM和Holter所测各波段振幅在肢体导联没有影响,胸导联振幅受体位影响而变化。     

Amplitude dependency of regional chest wall resistance and elastance at normal breathing frequencies

Current methods for measurement of chest wall properties assume that resistance (R) and elastance (E) are independent of the volume breathed. In six healthy subjects relaxed at functional residual capacity, we measured total and regional R and E of the chest wall within the range of normal breathing frequencies (0.2 to 0.6 Hz) and tidal volumes (250 to 750 ml), using volume forcing at the mouth as previously described. With these methods, esophageal and gastric pressures are compared with surface displacements measured with inductance plethysmographic belts to calculate R and E of rib cage and diaphragm-abdomen "pathways." Rib cage R and E were 25 to 30% higher than that of the total chest wall at each frequency and volume, whereas diaphragm-abdomen R and E were at least five times higher. R of the chest wall and each of the pathways decreased by about 70% with increasing frequency and by about 30% with increasing tidal volume. E of the chest wall and each of the pathways also decreased by about 30% with increasing tidal volume but was independent of frequency in this range. These results are consistent with nonlinear, viscoplastic models presented elsewhere. We conclude that: (1) despite the great structural differences between the rib cage and diaphragm-abdomen, each exhibits nonlinear behavior similar to that of the total chest wall; (2) chest wall R and E depend importantly on frequency and tidal volume.     

Transient midventricular ballooning syndrome. an atypical presentation of takotsubo cardiomyopathy

A 72-year-old woman without cardiovascular history presented with acute substernal chest pain and dyspnoea. The electrocardiogram was normal, but the blood test analyses showed an elevated troponin T level. Emergency coronary angiography revealed normal epicardial coronary arteries, but the left ventriculogram demonstrated midventricular dilatation and akinesis with well-preserved contractility of the apex and base. The patient was diagnosed as having an atypical presentation of takotsubo cardiomyopathy. She was treated with a beta blocker and an ACE inhibitor and recovered well. A follow-up echocardiogram at 2 months showed normalization of the wall motion abnormality.     

New guidelines for the clinical diagnosis of mitral valve prolapse

Because the term mitral valve prolapse has pathologic connotations, considerable effort has been expended to establish acceptable diagnostic standards, but without general agreement. This report combines information from the history, physical examination, electrocardiogram, chest x-ray and 2-dimensional echocardiogram in an effort to avoid the artifice of using the 2-dimensional echocardiogram as a categoric reference standard and to establish new clinical guidelines that distinguish pathologic mitral valve prolapse--a primary connective tissue abnormality of leaflets, chordae tendineae and anulus--from normal superior systolic displacement of mitral leaflets. The objective is to avoid implications of heart disease in healthy young persons within the gaussian distribution of normal. To this end, and with the Jones criteria as a model, major and minor criteria are proposed for the clinical diagnosis of mitral valve prolapse as a pathologic entity.     

Hypoplasia of the left ventricle: Rare cause of postoperative mortality in tetralogy of Fallot

Severe left ventricular hypoplasia in tetralogy of Fallot is a rare complication. A case history of a 3 year old child who died after attempted repair of tetralogy is presented. Left ventricular end-diastolic volume was 26 ml/m² (only 45 percent of predicted normal) after repair with normal filling pressure and no evidence of tamponade. Clinical examination, chest X-ray film, electrocardiogram and qualitative assessment of a preoperative left ventriculogram were not useful in assessing this degree of left ventricular hypoplasia; quantitative determination of left ventricular volumes is required for this purpose. When left ventricular end-diastolic volume is less than 55 percent of predicted normal, a shunt procedure may be indicated as an initial procedure with subsequent repair 1 to 2 years later, after left ventricular enlargement.     

Patterns of pulmonary perfusion scans in normal subjects. IV. The prevalence of abnormal scans in smokers 30 to 49 years of age

The usefulness of ventilation-perfusion scans in the diagnosis of pulmonary embolism is limited by the wide range of pulmonary diseases that are associated with abnormal scans, and by the largely undetermined prevalence of abnormal scans in persons without cardiopulmonary disease. In prior studies, we found perfusion defects to be rarely present in young persons and in older nonsmokers. To determine if normal older smokers have a higher prevalence of abnormal ventilation and perfusion scans, we performed six-view 99mTc perfusion (Q) scans and 133Xe ventilation (V) scans in 40 subjects 30 to 49 yr of age who had no known cardiopulmonary disease. Each subject had undergone a history, physical examination, electrocardiogram, spirometry, and posteroanterior chest roentgenogram prior to scanning. All V and Q scans were interpreted blindly and independently by two experienced readers. No subject demonstrated a lobar or segmental defect on two views. One subject had a matched subsegmental defect, and one subject had delayed washout from a subsegmental area of the right upper lobe during V scanning, with a normal Q scan. We conclude that abnormal V and Q scans are uncommon among normal smokers 30 to 49 yr of age.