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The axis
Published in Andrew R Houghton, Making Sense of the ECG, 2019
Left axis deviation may be a feature of myocardial infarction affecting the inferior aspect of the heart (the QRS axis is directed away from infarcted areas). The diagnosis will usually be apparent from the presentation and other ECG findings. For more information on the diagnosis and treatment of acute myocardial infarction, see Chapter 15.
Recognition of common arrhythmias
Published in John Edward Boland, David W. M. Muller, Interventional Cardiology and Cardiac Catheterisation, 2019
Nicholas P. Kerr, Rajesh N. Subbiah
RBBB produces an rSR’ pattern in lead V1 and a wide, slurred S wave in leads I and V6. The frontal plane axis is usually normal. Left bundle branch block (LBBB) produces a QS or rS pattern in V1, and a broad, slurred, monophasic R wave in leads I, aVL and V6. There may be left axis deviation, or the axis may be normal. When the QRS duration is greater than 120 ms, the bundle branch block is complete. Incomplete bundle branch block occurs when the same patterns are present but the QRS duration is 110–120 ms. Bundle branch blocks cause secondary abnormalities in repolarisation that manifest as displacement of the ST segment and T wave in the opposite direction to the major QRS deflection (i.e. the ST-T changes are discordant in direction to the QRS complex). Non-specific intraventricular conduction delay refers to QRS widening or abnormal fractionation that does not fit the patterns of typical left or right bundle branch block.
The axis
Published in Andrew R Houghton, David Gray, Making Sense of the ECG, 2014
Left axis deviation may be a feature of myocardial infarction affecting the inferior aspect of the heart (the QRS axis is directed away from infarcted areas). The diagnosis will usually be apparent from the presentation and other ECG findings. For more information on the diagnosis and treatment of acute myocardial infarction, see Chapter 9.
An unusual case of severe hypercalcemia: as dehydrated as a bone
Published in Journal of Community Hospital Internal Medicine Perspectives, 2021
Roshan Acharya, Dylan M Winters, Cameron Rowe, Nathan Buckley, Smita Kafle, Bhaskar Chhetri
In the emergency department, the rectal temperature was 37°Celsius, heart rate was 71 bpm, blood pressure was 181/75 mmHg, respiratory rate was 17 per min, and oxygen saturation was 99% on room air. On the physical examination the patient was lethargic, with Glasgow Coma Scale 13/15. The mucus membranes were extremely dry. The abdomen was soft, nontender, and no ascites were present. Deep tendon reflexes were 2+ bilaterally. She was oriented to self only. The lab work revealed hemoglobin 11.1 gm/dL, platelet count 128 x103/µL, serum sodium of 144 mmol/L, potassium 2.7 mmol/L, magnesium 1.1 mg/dL, blood urea nitrogen (BUN) of 23 mg/dL, creatinine 2.04 mg/dL, calcium 18.0 mg/dL with corrected calcium level of 19.0 mg/dL, serum albumin 3.2 g/dL, lactate 1.3 mmol/L, and ammonia 31 µg/dL. The comparison of the blood work from a week ago suggested hemoconcentration with acute kidney injury (Table 1). The Electrocardiogram demonstrated sinus rhythm, left axis deviation without ST-segment changes. Chest X-ray did not reveal perihilar lymphadenopathy, acute infiltrates, or effusion. CAT scan of the head without contrast demonstrated no evidence of intracranial pathology or mass. The patient was given 2-g intravenous magnesium sulfate, 80 mEq oral potassium, and 10 mg intravenous potassium chloride, and 200 units intramuscular calcitonin. The patient was admitted to the telemetry floor where she was started on normal saline infusion at the rate of 125 mL/hr.
Eisenmenger syndrome and other types of pulmonary arterial hypertension related to adult congenital heart disease
Published in Expert Review of Cardiovascular Therapy, 2019
Carla Favoccia, Andrew H Constantine, Stephen J Wort, Konstantinos Dimopoulos
An ECG can be useful in raising the suspicion of PH. In CHD, ECG changes related to the underlying defect or resultant physiological manifestations may also signify PH: High P wave amplitude (‘P pulmonale’), rightward QRS axis, bundle branch block, high amplitude ECG voltage or signs of right ventricular dominance (Figure 1). When present on ECGs of CHD patients, these changes can masquerade as PH or mask evolving PH. Expert evaluation and comparison with previous ECGs is required to pick up subtle ECG changes over time. Features on an ECG can also provide information regarding the underlying diagnosis in ES. For example, left axis deviation with a first-degree AV-block in an ES patient (especially in the presence of Down syndrome) is likely to be associated with a complete atrioventricular septal defect rather than an isolated VSD. Finally, the ECG can detect arrhythmias, which are common in PAH-CHD [21] and, without early identification and treatment, can easily lead to decompensation in patients with PH [22].
Respiratory insufficiency from myasthenia gravis and polymyositis due to malignant thymoma triggering Takotsubo syndrome
Published in International Journal of Neuroscience, 2018
Josef Finsterer, Claudia Stöllberger, Chen-Yu Ho
On admission, the ECG showed left axis deviation and normocardious sinus rhythm but was otherwise normal. During swallowing of acetyl-salicylic acid and clopidogrel on hospital day 1 (hd1), she experienced a respiratory arrest, requiring cardio-pulmonary resuscitation (CPR), intubation and mechanical ventilation. Transthoracic echocardiography revealed a globally reduced systolic function, a small pericardial effusion and typical apical ballooning being interpreted as TTS. Tachycardious atrial fibrillation was first recorded shortly after CPR and successfully cardioverted with amiodarone. Additionally, there was anemia, renal insufficiency, hypo-/hyper-calcemia, hypoproteinemia, proteinurea, hypoparathyroidism, vitamin-D deficiency, positive MPO antibodies, low cholinesterase, elevated γ-globulin, a monoclonal paraprotein-IgG-kappa and elevated liver function parameters (Table 2). Mild hyper-CKemia persisted until hd15 (Table 2). On hd3, the patient awaked. Coronary angiography was normal but ventriculography showed apical ballooning, typical of classical TTS (Figure 1). Clopidogrel was discontinued. She was extubated on hd6. Unfortunately, she had to be re-intubated the same day because of recurrence of muscular respiratory insufficiency. Repeated ECGs after CPR showed permanent right bundle branch block. Echocardiography normalised within 7 weeks after admission.