St depression ecg

• Basic anatomy & physiology • Introduction to ECG Interpretation • Arrhythmias and arrhythmology • Myocardial Ischemia & Infarction • Conduction Defects • Cardiac Hypertrophy & Enlargement • Drugs & Electrolyte Imbalance • Genetics, Syndromes & Miscellaneous • Exercise Stress Testing (Exercise ECG) • Pacemaker & CRT • Pediatric & neonatal ECG • ECHO • SCA & CPR • TAKE A TEST • POPULAR Non ST Elevation Acute Coronary Syndromes (NSTE-ACS): Non ST Elevation Myocardial Infarction (NSTEMI) and Unstable Angina (UA) The focus of this chapteris the diagnosis and management of patients with Non ST Elevation Myocardial Infarction (NSTEMI) and unstable angina (UA), which are collectively referred to as NSTE-ACS (Non ST Elevation As in partial(incomplete) coronary artery occlusions; a partial occlusion results in a reduction of coronary blood flow and this causes subendocardial ischemia (i.e ischemia that only affects the subendocardium). STEMI, on the other hand, is caused by a complete coronary artery occlusion, which results in complete stop of blood flow and thus more extensive As in patients with STEMI, those with NSTEMI and unstable angina are at considerable risk of developing life-threatening ventricular arrhythmias ( NSTEMI & unstable angina: different but similar NSTEMI and unstable angina are different in one fundamental aspect: NSTEMI is by definition an no evidence of myocardial infarction (necrosis). However, unstable angina is considered an acute coronary syndrome beca...

The ST segment: physiology, normal appearance, ST depression & ST elevation The ST segment corresponds to the plateau phase of the Figure 13). The ST segment extends from the J point to the onset of the T-wave. Because of the long duration of the plateau phase most contractile cells are in this phase at the same time (more or less). Moreover, the membrane potential is relatively unchanged during the plateau phase. These two factors are the reason why the ST segment is flat and isoelectric (i.e in level with the baseline). Figure 13. Displacement of the ST segment is of fundamental importance, particularly in acute Figure 13 for examples. Figure 14 below shows how to measure ST segment deviation. Figure 14. Example of measuring ST deviation (elevation and depression). The following must be noted regarding the ST segment: • The normal ST segment is flat and isoelectric. The transition from ST segment to T-wave is smooth, and not abrupt. • ST segment deviation (elevation, depression) is measured as the height difference (in millimeters) between the J point and the baseline (the PR segment). ST segment deviation occurs in a wide range of conditions, particularly acute myocardial ischemia. • Because the ST segment and the T-wave are electrophysiologically related, changes in the ST segment are frequently accompanied by It must also be noted that the J point is occasionally suboptimal for measuring ST segment deviation. This is explained by the fact that the J point is not alway...

• Basic anatomy & physiology • Introduction to ECG Interpretation • Arrhythmias and arrhythmology • Myocardial Ischemia & Infarction • Conduction Defects • Cardiac Hypertrophy & Enlargement • Drugs & Electrolyte Imbalance • Genetics, Syndromes & Miscellaneous • Exercise Stress Testing (Exercise ECG) • Pacemaker & CRT • Pediatric & neonatal ECG • ECHO • TAKE A TEST • POPULAR ECG changes due toelectrolyteimbalance (electrolyte disorder) The normal cardiac Specific electrolyte disorders 1. Sodium Increased (hypernatremia) and decreased (hyponatremia) sodium levels donot have any effect on the ECG, nor cardiac rhythm, or impulse conduction. 2. Calcium Hypercalcemia Causes of hypercalcaemia Primary hyperparathyroidism and malignancies cause 90% of all cases of hypercalcemia. Less common causes are immobilization, sarcoidosis,thyrotoxicosis,familial hypocalciuric hypercalcemia, Addison’s disease, renal failure, tamoxifen, lithium, thiazide diuretics, D vitamin and calcium overdose. ECG changes due to hypercalcemia • Common ECG changes • ShortenedQT interval. • Lengthened QRS duration. • Bradycardia may occur. • Rare ECG changes • Increased QRS amplitude. • Diminished T-wave amplitude • Osborn-like waves. • • All degrees of AV block. • • Hypocalcemia Causes of hypocalcemia Acute pancreatitis, pancreas surgery, alkalosis (hyperventilation), rhabdomyolysis, septicemia (sepsis), osteolytic cancer metastases, abnormal calcium absorption (gastrointestinal) and resorption (from primary...

Methods and results We investigated the association between silent ST-segment depression during and after maximal symptom-limited exercise test and the risk of sudden cardiac death in a population-based sample of 1769 men without evident CHD. A total of 72 sudden cardiac death occurred during the median follow-up of 18 years. The risk of sudden cardiac death was increased among men with asymptomatic ST-segment depression during exercise [hazard ratio (HR) 2.1, 95% confidence interval (CI) 1.2–3.9] as well as among those with asymptomatic ST-segment depression during recovery period (HR 3.2, 95% CI 1.7–6.0). Asymptomatic ST-depression during exercise testing was a stronger predictor for the risk of sudden cardiac death especially among smokers as well as in hypercholesterolaemic and hypertensive men than in men without these risk factors. Introduction It is known that coronary heart disease (CHD) may develop during the decades without typical symptoms and thus early recognization of vulnerable CHD would be very difficult. Clinical studies have been largely unsuccessful in identifying specific markers of sudden cardiac death risk in the general population. It is suggested that exercise testing may be recommended among those with the presence of at least one conventional risk factor. Methods Subjects This study was designed to investigate risk factors for CHD in a population-based sample of men from eastern Finland. Subjects were randomly selected sample of 3433 men aged 42–6...

10. ST Segment Abnormalities Topics for study: • • • General Introduction to ST, T, and U wave abnormalities Basic Concept: the specificity of ST-T and U wave abnormalities is provided more by the clinical circumstances in which the ECG changes are found than by the particular changes themselves. Thus the term, nonspecific ST-T wave abnormalities, is frequently used when the clinical data are not available to correlate with the ECG findings. This does not mean that the ECG changes are unimportant! It is the responsibility of the clinician providing care for the patient to ascertain the importance of the ECG findings. Factors affecting the ST-T and U wave configuration include: • Intrinsic myocardial disease (e.g., myocarditis, ischemia, infarction, infiltrative or myopathic processes) • Drugs (e.g., digoxin, quinidine, tricyclics, and many others) • Electrolyte abnormalities of potassium, magnesium, calcium • Neurogenic factors (e.g., stroke, hemorrhage, trauma, tumor, etc.) • Metabolic factors (e.g., hypoglycemia, hyperventilation) • Atrial repolarization (e.g., at fast heart rates the atrial T wave may pull down the beginning of the ST segment) • Ventricular conduction abnormalities and rhythms originating in the ventricles "Secondary" ST-T Wave changes (these are normal ST-T wave changes solely due to alterations in the sequence of ventricular activation): • ST-T changes seen in bundle branch blocks (generally the ST-T polarity is opposite to the major or terminal defle...

Definition of normal and pathological pediatric and neonatal ECG The neonatal and pediatric electrocardiogram ( • Heart rate • Rhythm • P-wave • PR interval • QRS complex • ST-segment • T-wave • U-wave • QT (QTc) interval Pediatric and neonatal electrocardiograms differ markedly – in terms of rhythm, morphology, normal findings, normal variants, etc – from adult electrocardiograms. It is crucial to be familiar with normal findings, normal variants, and pathology in neonates, infants and during the childhood years. Below follows a discussion on each of the nine parameters listed above. Many of the diagnoses mentioned below are discussed in detail in other chapters, to which links are provided throughout the text. Heart rate During the first week of life, the heart rate is approximately 120 beats/min. The heart rate then increases during the first 1 to 2 months to about 150 beats/min. It then gradually decreases to about 120 beats/min at 6 months of age. After 12 months of age, the heart rate is steadily decreasing, and by age 10 years the rate is the same as in adults. These age variations in heart rate are due to variations in the activity of the autonomic nervous system and changes in the Rhythm Normal rhythm A rhythm is defined as three consecutive beats with identical waveforms on the ECG. The similarity of the waveforms indicates that the origin of the impulse is the same. The sinoatrial (SA) node is the heart’s pacemaker under normal circumstances and the rhythm is re...

10. ST Segment Abnormalities Topics for study: • • • General Introduction to ST, T, and U wave abnormalities Basic Concept: the specificity of ST-T and U wave abnormalities is provided more by the clinical circumstances in which the ECG changes are found than by the particular changes themselves. Thus the term, nonspecific ST-T wave abnormalities, is frequently used when the clinical data are not available to correlate with the ECG findings. This does not mean that the ECG changes are unimportant! It is the responsibility of the clinician providing care for the patient to ascertain the importance of the ECG findings. Factors affecting the ST-T and U wave configuration include: • Intrinsic myocardial disease (e.g., myocarditis, ischemia, infarction, infiltrative or myopathic processes) • Drugs (e.g., digoxin, quinidine, tricyclics, and many others) • Electrolyte abnormalities of potassium, magnesium, calcium • Neurogenic factors (e.g., stroke, hemorrhage, trauma, tumor, etc.) • Metabolic factors (e.g., hypoglycemia, hyperventilation) • Atrial repolarization (e.g., at fast heart rates the atrial T wave may pull down the beginning of the ST segment) • Ventricular conduction abnormalities and rhythms originating in the ventricles "Secondary" ST-T Wave changes (these are normal ST-T wave changes solely due to alterations in the sequence of ventricular activation): • ST-T changes seen in bundle branch blocks (generally the ST-T polarity is opposite to the major or terminal defle...

Non ST Elevation Acute Coronary Syndromes (NSTE-ACS): Non ST Elevation Myocardial Infarction (NSTEMI) and Unstable Angina (UA) The focus of this chapteris the diagnosis and management of patients with Non ST Elevation Myocardial Infarction (NSTEMI) and unstable angina (UA), which are collectively referred to as NSTE-ACS (Non ST Elevation As in partial(incomplete) coronary artery occlusions; a partial occlusion results in a reduction of coronary blood flow and this causes subendocardial ischemia (i.e ischemia that only affects the subendocardium). STEMI, on the other hand, is caused by a complete coronary artery occlusion, which results in complete stop of blood flow and thus more extensive As in patients with STEMI, those with NSTEMI and unstable angina are at considerable risk of developing life-threatening ventricular arrhythmias ( NSTEMI & unstable angina: different but similar NSTEMI and unstable angina are different in one fundamental aspect: NSTEMI is by definition an no evidence of myocardial infarction (necrosis). However, unstable angina is considered an acute coronary syndrome because it is an imminent precursor to myocardial infarction. Approximately 50% of patients with unstable angina progress to myocardial infarction within 30 days if left untreated. Moreover, the pathophysiology of NSTEMI and unstable angina is very similar: both are due to partial (incomplete) coronary artery occlusions, which implies that there remains residual blood flow in the artery. Mo...

• Basic anatomy & physiology • Introduction to ECG Interpretation • Arrhythmias and arrhythmology • Myocardial Ischemia & Infarction • Conduction Defects • Cardiac Hypertrophy & Enlargement • Drugs & Electrolyte Imbalance • Genetics, Syndromes & Miscellaneous • Exercise Stress Testing (Exercise ECG) • Pacemaker & CRT • Pediatric & neonatal ECG • ECHO • TAKE A TEST • POPULAR ECG changes due toelectrolyteimbalance (electrolyte disorder) The normal cardiac Specific electrolyte disorders 1. Sodium Increased (hypernatremia) and decreased (hyponatremia) sodium levels donot have any effect on the ECG, nor cardiac rhythm, or impulse conduction. 2. Calcium Hypercalcemia Causes of hypercalcaemia Primary hyperparathyroidism and malignancies cause 90% of all cases of hypercalcemia. Less common causes are immobilization, sarcoidosis,thyrotoxicosis,familial hypocalciuric hypercalcemia, Addison’s disease, renal failure, tamoxifen, lithium, thiazide diuretics, D vitamin and calcium overdose. ECG changes due to hypercalcemia • Common ECG changes • ShortenedQT interval. • Lengthened QRS duration. • • Rare ECG changes • Increased QRS amplitude. • Diminished T-wave amplitude • Osborn-like waves. • • All degrees of AV block. • • Hypocalcemia Causes of hypocalcemia Acute pancreatitis, pancreas surgery, alkalosis (hyperventilation), rhabdomyolysis, septicemia (sepsis), osteolytic cancer metastases, abnormal calcium absorption (gastrointestinal) and resorption (from primary urine), renal failure,...

Definition of normal and pathological pediatric and neonatal ECG The neonatal and pediatric electrocardiogram ( • Heart rate • Rhythm • P-wave • PR interval • QRS complex • ST-segment • T-wave • U-wave • QT (QTc) interval Pediatric and neonatal electrocardiograms differ markedly – in terms of rhythm, morphology, normal findings, normal variants, etc – from adult electrocardiograms. It is crucial to be familiar with normal findings, normal variants, and pathology in neonates, infants and during the childhood years. Below follows a discussion on each of the nine parameters listed above. Many of the diagnoses mentioned below are discussed in detail in other chapters, to which links are provided throughout the text. Heart rate During the first week of life, the heart rate is approximately 120 beats/min. The heart rate then increases during the first 1 to 2 months to about 150 beats/min. It then gradually decreases to about 120 beats/min at 6 months of age. After 12 months of age, the heart rate is steadily decreasing, and by age 10 years the rate is the same as in adults. These age variations in heart rate are due to variations in the activity of the autonomic nervous system and changes in the Rhythm Normal rhythm A rhythm is defined as three consecutive beats with identical waveforms on the ECG. The similarity of the waveforms indicates that the origin of the impulse is the same. The sinoatrial (SA) node is the heart’s pacemaker under normal circumstances and the rhythm is re...