Section 9 Technical issues Electrical interference Skeletalmuscle interference Regular skeletal muscle interference ‘Technical’ dextrocardia Misplaced chest leads Case 84 A routine preoperative recording Electrical interference • A regular wave at 50-60 Hz superimposed on the recording. Features of this ECG • Sinus rhythm, 66 b.p.m., normal QRS axis • Features of electrical interference (Fig. 84.1): – a regular wave thickening the baseline • Otherwise normal recording Fig. 84.1 Lead II. Clinical Note Electrical interference is usually due to poor electrode contact, earthing problems or faulty equipment. It often distorts the finer detail of a recording. Case 85 A young man with non-specific chest pain Skeletal muscle interference • Irregular high frequency spikes of skeletal muscle contractions. Features of this ECG • Sinus rhythm, 72 b.p.m., normal QRS axis • Features of skeletal muscle interference (Fig. 85.1): – high frequency spikes • Otherwise normal recording Fig. 85.1 Lead II. Clinical Note Skeletal muscle interference is usually due to a nervous and tense patient. Ensure that the patient is calm with their head resting on a pillow and arms relaxed at each side. In a patient in pain or distress it is important to repeat the recording until the best possible trace is obtained. Sometimes a regular skeletal muscle interference may be due to a tremor such as in Parkinson’s disease. Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Hypertrophy patterns Bundle branch block Ventricular rhythms Ischaemic heart disease Stay updated, free articles. Join our Telegram channel Join Tags: ECGs by Example Aug 29, 2016 | Posted by admin in CARDIOLOGY | Comments Off on Technical issues Full access? Get Clinical Tree
Section 9 Technical issues Electrical interference Skeletalmuscle interference Regular skeletal muscle interference ‘Technical’ dextrocardia Misplaced chest leads Case 84 A routine preoperative recording Electrical interference • A regular wave at 50-60 Hz superimposed on the recording. Features of this ECG • Sinus rhythm, 66 b.p.m., normal QRS axis • Features of electrical interference (Fig. 84.1): – a regular wave thickening the baseline • Otherwise normal recording Fig. 84.1 Lead II. Clinical Note Electrical interference is usually due to poor electrode contact, earthing problems or faulty equipment. It often distorts the finer detail of a recording. Case 85 A young man with non-specific chest pain Skeletal muscle interference • Irregular high frequency spikes of skeletal muscle contractions. Features of this ECG • Sinus rhythm, 72 b.p.m., normal QRS axis • Features of skeletal muscle interference (Fig. 85.1): – high frequency spikes • Otherwise normal recording Fig. 85.1 Lead II. Clinical Note Skeletal muscle interference is usually due to a nervous and tense patient. Ensure that the patient is calm with their head resting on a pillow and arms relaxed at each side. In a patient in pain or distress it is important to repeat the recording until the best possible trace is obtained. Sometimes a regular skeletal muscle interference may be due to a tremor such as in Parkinson’s disease. Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Hypertrophy patterns Bundle branch block Ventricular rhythms Ischaemic heart disease Stay updated, free articles. Join our Telegram channel Join Tags: ECGs by Example Aug 29, 2016 | Posted by admin in CARDIOLOGY | Comments Off on Technical issues Full access? Get Clinical Tree
