Tall t wave

Enter search terms to find related medical topics, multimedia and more. Advanced Search: • Use “ “ for phrases o [ “pediatric abdominal pain” ] • Use – to remove results with certain terms o [ “abdominal pain” –pediatric ] • Use OR to account for alternate terms o [teenager OR adolescent ] Search A-Z Hyperkalemia is a serum potassium concentration > 5.5 mEq/L (> 5.5 mmol/L), usually resulting from decreased renal potassium excretion or abnormal movement of potassium out of cells. There are usually several simultaneous contributing factors, including increased potassium intake, drugs that impair renal potassium excretion, and acute kidney injury or chronic kidney disease. Hyperkalemia can also occur in metabolic acidosis (eg, as in diabetic ketoacidosis). Clinical manifestations are generally neuromuscular, resulting in muscle weakness and cardiac toxicity that, when severe, can degenerate to ventricular fibrillation or asystole. Diagnosis is by measuring serum potassium. Treatment may involve decreasing potassium intake, adjusting drugs, giving a cation exchange resin and, in emergencies, giving calcium gluconate, insulin, and dialysis. Pseudohyperkalemia is most often caused by hemolysis of red blood cells in a blood sample. Pseudohyperkalemia can also occur as a result of prolonged application of a tourniquet or excessive fist clenching when venous blood is drawn. Thrombocytosis can cause pseudohyperkalemia in serum (platelet potassium is released during clotting), as ca...

ECG Library Homepage Hypokalaemia is defined as a serum potassium level of < 3.5 mmol/L. ECG changes generally do not manifest until there is a moderate degree of hypokalaemia (2.5-2.9 mmol/L). The earliest ECG manifestation of hypokalaemia is a decrease in T wave amplitude. ECG features of hypokalaemia (K < 2.7 mmol/L) • Increased P wave amplitude • Prolongation of PR interval • Widespread ST depression and T wave flattening/inversion • Prominent 2-V 3) • Apparent long QT interval due to fusion of T and U waves (= long QU interval) With worsening hypokalaemia… • Frequent supraventricular and ventricular ectopics • Supraventricular tachyarrhythmias: AF, atrial flutter, atrial tachycardia • Potential to develop life-threatening ventricular arrhythmias, e.g. VT, VF and Torsades de Pointes • Hypokalaemia creates the illusion that the T wave is “pushed down”, with resultant T-wave flattening/inversion, ST depression, and prominent U waves • In hyperkalaemia, the T wave is “pulled upwards”, creating tall “tented” T waves, and stretching the remainder of the ECG to cause P wave flattening, PR prolongation, and QRS widening Pathophysiology Potassium is vital for regulating the normal electrical activity of the heart. Decreased extracellular potassium causes myocardial hyperexcitability with the potential to develop re-entrant arrhythmias. Degree of hypokalaemia Potassium level (mmol/L) Mild 3.0 – 3.4 Moderate 2.5 – 2.9 Severe ≤ 2.4 Classification of severity of hypokalaemia Handy...

The normal T-wave Assessment of the T-wave represents a difficult but fundamental part of Figure 17). Otherwise there is discordance (opposite directions of QRS and T) which might be due to pathology. A negative T-wave is also called an inverted T-wave. Figure 17. Discordance and concordance between QRS and ST-T. T-wave changes are notoriously misinterpreted, particularly Figure 18. Figure 18. Normal and pathological T-waves. Positive T-waves Positive T-waves are rarely higher than 6 mm in the limb leads (typically highest in lead II). In the chest leads the amplitude is highest in V2–V3, where it may occasionally reach 10 mm in men and 8 mm in women. Usually, though, the amplitude in V2–V3 is around 6 mm and 3 mm in men and women, respectively. T-waves that are higher than 10 mm and 8 mm, in men and women, respectively, should be considered abnormal. A common cause of abnormally large T-waves is hyperkalemia, which results in high, pointed and asymmetric T-waves. These must be differentiated from hyperacute T-waves seen in the very early phase of T-wave inversion (inverted / negative T-waves) T-wave inversion means that the T-wave is negative. The T-wave is negative if its terminal portion is below the baseline, regardless of whether its other parts are above the baseline. T-wave inversions are frequently misunderstood, particularly in the setting of ischemia. Normal T-wave inversion An isolated (single) T-wave inversion in lead V1 is common and normal. It is generally co...

• Normally upright in 1, 2, V3-V6 • Normally inverted in AVR and V1 • Sometimes inverted in III, aVF, aVL, V1 • New upright T wave in V1 or T wave taller in V1 than in V6 is pathologic • Inversions in V2-V6 are usually pathologic • Exception is persistent juvenile T-wave pattern, usually limited to V1-V3, classically young Afro-Caribbean women • Greater than 2/3 height of R wave is abnormal • Morphology • Inverted, symmetric, • Transient changes suggests ischemia without infarction • Persistent changes suggests infarction ( • Pseudonormalization • In presence of baseline TWI (within 1 month), reocclusion causes normalization of TWI • Should be interpreted as evidence of ischemia New Tall T-wave in V1 • Loss of precordial T-wave balance when upright TW in V1 > upright TW in V6 • A form of hyperacute T-wave • New Tall T-Wave in V1 (NTTV1) = upright T-wave in V1, especially with proven change from previous ECG • Concerning for ischemia, especially with ACS symptomology • Perform repeat ECGs • Normal variants • Misplaced leads • • • High left ventricular voltage Differential Diagnosis • Normal in pediatrics • • Myocardial ischemia ( • • • • • Pulmonary disease - hyperventilation, • • • • • • CNS T waves (diffuse, deep) • • • Paced rhythm • • • • • See Also • • References

I. Wide QRS Tachycardia: What every physician needs to know. A. Wide Complex Tachycardia: Definition of Wide and Narrow Related Topics Aberrancy, ventricular tachycardia, supraventricular tachycardia, right-bundle branch block (RBBB), left-bundle branch block (LBBB), intraventricular conduction delay (IVCD), pre-excited tachycardia. • propagation of a supraventricular impulse (atrial premature depolarizations [APDs] or supraventricular tachycardia [SVT]) with block (preexisting or rate-related) in one or more parts of the His-Purkinje network; • depolarizations originating in the ventricles themselves (ventricular premature beats [VPDs] or ventricular tachycardia [VT]); • slowed propagation of a supraventricular impulse because of intra-myocardial scar/fibrosis/hypertrophy; or • conduction of a supraventricular impulse from atrium to ventricle over an accessory pathway (bypass tract) – so called “pre-excited” tachycardia. II. Diagnostic Confirmation: Are you sure your patient has Wide QRS Tachycardia? What determines the width of the QRS complex? The clinical situation that is commonly encountered is when the clinician is faced with an electrocardiogram (ECG) that shows a The width of the QRS complex, both with aberrancy and during VT, can vary from patient to patient. Scar tissue, as seen in patient with prior myocardial infarctions or with cardiomyopathy, may further slow intramyocardial conduction, resulting in wider QRS complexes in both situations. During VT, the widt...

Hyperkalemia is an elevated concentration of the serum potassium higher than 5.5 mEq/L. Hyperkalemia normally cause characteristic changes on the electrocardiogram, which are of vital importance to ensure a quick diagnosis and to estimate the the severity of the hyperkalemia. Severe hyperkalemia is a life-threatening medical condition, for this reason, it is important to recognize its electrocardiographic findings. Serum Potassium About 98% of the total body potassium is found inside cells, and the remaining 2% is in the extracellular space. High levels of serum potassium cause Hyperkalemia decrease the resting membrane potential of cardiac myocytes and therefore partially depolarize the cell membrane. This change decreases cardiac contractility and can cause 1. The most common causes of hyperkalemia are kidney failure and treatment with ACEi, ARBs or potassium-sparing diuretics. Also can result from other disturbances such as metabolic acidosis, primary Addison syndrome, extensive cell damage (burns, trauma...), among others. Hyperkalemia Definitions: Normal serum potassium levels are between 3.5 mEq/L and 5.0 mEq/L. Levels above 5.5 mEq/L indicate hyperkalemia. Electrocardiogram and Hyperkalemia EKG should be done on patients with suspected hyperkalemia or high potassium levels in a blood test in order to determine the severity of hyperkalemia. The diagnosis of hyperkalemia is usually made by its typical EKG findings. Severity of Hyperkalemia Electrocardiogram changes or...

The Electrocardiogram (ECG) The ECG is a graphic record of the heart's electrical activity plotted over time. It is a very useful test which is easy to perform and readily available. This lecture is a revision of the many uses and the practical application of electrocardiography in small animals. Uses of Electrocardiography For the diagnosis of arrhythmias noted on clinical examination To rule out arrhythmias in animals with a history of collapse To provide information regarding chamber enlargement To provide information on certain electrolyte disturbances To provide supportive evidence of a diagnosis of pericardial effusion To monitor effectiveness of anti-arrhythmic therapy To monitor the heart rhythm under anaesthesia Lead Systems ECG electrodes are attached at multiple sites on the body to allow the electrical activity of the heart to be viewed from multiple angles. The standard leads are the bipolar limb leads I, II and III and the augmented limb leads aVR, aVL and aVF. Chest leads are sometimes recorded for further evaluation of cardiac chamber size, however these will not be covered in this lecture. Leads I, II, and III compare electrical impulses between electrodes placed on two limbs. Leads aVR, aVL and aVF compare the signal at one limb with the average of the two other limbs. These are mainly used to calculate mean electrical axis. Lead II is used to make the standard measurements of the P-QRS-T waveform. ECG P-QRS -T Wave Form The typical sinus electrical impul...

Tall peaked T waves Tall peaked T waves are seen in leads V2-V4 (C2-C4). In addition there is prominent negative component for P wave in lead V1 (C1) suggestive of left atrial enlargement and tall R waves in V5, V6 (C5, C6) indicating left ventricular hypertrophy. Tall T waves could occur both in Rarely, tall T waves can occur in acidosis without hyperkalemia [2]. In this study amplitude of T wave in V2 was positively correlated with hydrogen ion concentration. These T waves were also symmetrical and narrow based, the so called ‘tent shaped T waves’. The T waves were taller during acidosis than after correction. In this ECG, in addition to tall T waves (more peaked than in previous ECG), QRS complex is wide and has left bundle branch block pattern. There is ST segment depression and T wave inversion in the lateral leads, though the T waves are very tall and peaked in mid precordial leads. Left bundle branch block pattern is characterized by the wide notched QRS complexes in lead V6 with secondary repolarization abnormality in the form of ST segment depression and T wave inversion. the opposite pattern of a wide S wave with upsloping ST and upright T is seen in V1. References • Pardee HEB. An electrocardiographic sign of coronary artery obstruction. Arch Intern Med 1920; 26: 244– 257. • Dreyfuss D, Jondeau G, Couturier R, Rahmani J, Assayag P, Coste F.

Hyperkalemia is an elevated concentration of the serum potassium higher than 5.5 mEq/L. Hyperkalemia normally cause characteristic changes on the electrocardiogram, which are of vital importance to ensure a quick diagnosis and to estimate the the severity of the hyperkalemia. Severe hyperkalemia is a life-threatening medical condition, for this reason, it is important to recognize its electrocardiographic findings. Serum Potassium About 98% of the total body potassium is found inside cells, and the remaining 2% is in the extracellular space. High levels of serum potassium cause Hyperkalemia decrease the resting membrane potential of cardiac myocytes and therefore partially depolarize the cell membrane. This change decreases cardiac contractility and can cause 1. The most common causes of hyperkalemia are kidney failure and treatment with ACEi, ARBs or potassium-sparing diuretics. Also can result from other disturbances such as metabolic acidosis, primary Addison syndrome, extensive cell damage (burns, trauma...), among others. Hyperkalemia Definitions: Normal serum potassium levels are between 3.5 mEq/L and 5.0 mEq/L. Levels above 5.5 mEq/L indicate hyperkalemia. Electrocardiogram and Hyperkalemia EKG should be done on patients with suspected hyperkalemia or high potassium levels in a blood test in order to determine the severity of hyperkalemia. The diagnosis of hyperkalemia is usually made by its typical EKG findings. Severity of Hyperkalemia Electrocardiogram changes or...

The normal T-wave Assessment of the T-wave represents a difficult but fundamental part of Figure 17). Otherwise there is discordance (opposite directions of QRS and T) which might be due to pathology. A negative T-wave is also called an inverted T-wave. Figure 17. Discordance and concordance between QRS and ST-T. T-wave changes are notoriously misinterpreted, particularly Figure 18. Figure 18. Normal and pathological T-waves. Positive T-waves Positive T-waves are rarely higher than 6 mm in the limb leads (typically highest in lead II). In the chest leads the amplitude is highest in V2–V3, where it may occasionally reach 10 mm in men and 8 mm in women. Usually, though, the amplitude in V2–V3 is around 6 mm and 3 mm in men and women, respectively. T-waves that are higher than 10 mm and 8 mm, in men and women, respectively, should be considered abnormal. A common cause of abnormally large T-waves is hyperkalemia, which results in high, pointed and asymmetric T-waves. These must be differentiated from hyperacute T-waves seen in the very early phase of T-wave inversion (inverted / negative T-waves) T-wave inversion means that the T-wave is negative. The T-wave is negative if its terminal portion is below the baseline, regardless of whether its other parts are above the baseline. T-wave inversions are frequently misunderstood, particularly in the setting of ischemia. Normal T-wave inversion An isolated (single) T-wave inversion in lead V1 is common and normal. It is generally co...