Rhythm strip

Monitor the patient s 12-lead ECG or single rhythm strips to determine if an arrhythmia is present and to identify the specific arrhythmia, and evaluate and monitor the patient s symptoms. 

Periodically assess the 12-lead EGG and rhythm strips of patienf s wifh underlying arrhythmias... 

A 41-year-old woman, with liver lacerations, rib fractures, and pneumothorax after a motor vehicle accident, was given haloperidol for agitation on day 7. During the first 24 hours she received a cumulative intravenous dose of 15 mg, 70 mg on day 2, 190 mg on day 3,160 mg on days 4 and 5, and 320 mg on day 6. An hour after the first dose of 80 mg on day 7, she had ventricular extra beats followed by 5-beat and 22-beat runs of ventricular tachycardia. The rhythm strips were consistent with polymorphous ventricular tachycardia or torsade de pointes and the QTC interval was 610 ms (normally under 450 in women). She received intravenous magnesium sulfate 2 g. Concurrent medications included enoxaparin, famotidine, magnesium hydroxide, ampicillin/sulbactam, nystatin suspension, midazolam, and 0.45% saline with 20 mmol/1 of potassium chloride. She had no further dysrhythmias after haloperidol was withdrawn. Eight days after the episode of torsade de pointes she had a QTC interval of 426 ms. 

After administration Monitor cognitive, behavioral, and functional status of patient. Evaluate ECG, periodic rhythm strips in patient with underlying arrhythmias. Monitor for symptoms of ulcer, GI bleeding. 

FIGURE 40.1 ECG rhythm strip. The extension of the QT interval is termed QT prolongation. The ending point of the T wave sometimes is difficult to determine, which contributes to the variability of QT measurements. 

Dekker JM, Crow RS, Folsom AR, et al. Low heart rate variability in a 2-minute rhythm strip predicts risk of coronary heart disease and mortality from several causes the ARIC study. Atherosclerosis Risk In Communities. Circulation2000 102(11) 113—20. 

Reiter s syndrome Reye s syndrome rhythm strip right side... 

Sinus Bradycardia Increased parasympathetic (vagal) tone causes heart to beat at < 60 beats per minute. Depolarization originates from sinoatrial node (hence the name r sinus). Slow, but regular rate on rhythm strip. Not treated if asymptomatic. If patient deveiops angina, hypotension, heart failure or other symptoms, treat with Atropine Isoproterenol Epinephrine (Each OT these drugs induces sympathetic predominance)... 

FIGURE 24.4 This is an example of an interpreted 12 lead EGG. A 2.5 sec recording is shown for each of the 12 leads. The bottom trace is a continuous 10 sec rhythm strip of lead II. Patient information is given in the top area, below which is printed the computerized interpretive statements. (Diagram is courtesy of GE Healthcare Technologies, Waukesha, WI.)... 

Historically, device monitoring away from the clinic was accomplished transtelephonically. In these sessions, the patient dons wristband electrodes attached to a device that transmits a rhythm strip over a landline. More recently, advances in telecommunication technology have enabled the use of cell-phone-based transmission of essential data directly to a clinic, where it can be viewed via the Internet. This remote monitoring can provide valuable alerts when certain clinical criteria are met (Figure 11.7). 

Fig. 10.3 Diagrammatic representation of various forms of second-degree AV block with the same format as in Fig. 10.2. (A) Relatively long and atypical type I sequence with several constant PR intervals before a dropped beat. Note the shorter PR interval after the blocked P-wave. This pattern should not be called type 11 AV block. It is essential to examine all the PR intervals in long rhythm strips and not merely several PR intervals preceding a blocked impulse. (B) True type II AV block. Every atrial impulse successfully traverses the AV node which is not afforded a long recovery time as occurring in type I AV block. Note that the PR interval after the blocked beat is unchanged. Reproduced with permission from (11).

The current version of the device (Reveal Plus ) has programmable automatic detection of high and low heart rates, and pauses. The memory configuration allows for division of multiple 1-2 min automatic rhythm strips in addition to 1-3 manual recordings. Thus, in patients unable to manually activate the device, automatic event acquisition can occur to detect extreme heart rates or pauses as preprogrammed. 

Fig. 16.7 Continuous MCLl rhythm strip recorded from a patient with hyperkalemia, acidosis, and multiorgan failure. The serum potassium at this time was 7.6mEq/dL. All QRS complexes are broad and bizarre, and resemble sine waves compatible with hyperkalemia. Pacing stimuli are occurring at a rate of 70 per minute. None can be ascertained to be capturing ventricular tissue. Pacing cannot be restored without correction of the underlying abnormality.

There are multiple objectives associated with each follow-up evaluation. These may vary from one session to another and will determine the relative complexity of the particular session whether ancillary testing such as an echo-Doppler evaluation or chest x-ray is indicated or if the sole test that is required is a simple ECG rhythm strip. 

Fig. 19.17 The lead II rhythm strip on the left whieh was initially monitored had an absolutely isoelectric paced QRS giving the impression of noncapture with impressive asystolic pauses. The patient, however, was asymptomatic and the pulse was stable indicating that there was a heartbeat despite the absence of a visible QRS complex on the ECG. A lead III rhythm strip is shown on the right panel and clearly demonstrates the presence of effective capture associated with the ventricular output.

As with pacemaker analysis an electrocardiogram (EGG) cable can be attached to the patient to provide EGG rhythm strips. They can aid in assessing the pacing and sensing functions of the IGD. "Marker chaimel" annotations are also available. They vary from those for pacemakers in that additional annotations are used to delineate ventricular events that occur within the various IGD tachycardia treatment zones (i.e. "VT" for VT zone or "VE" for VF zone for the below example). These tachycardia annotations differ between IGD manufacturers, but tend to convey similar information. 

The thresholds of right and left ventricular pacing leads can be difficult to assess in ICDs that do not have separate programmability for each output. This is because the morphology change of the QRS complex on a single surface ECG rhythm strip can be very subtle when capture is lost in a ventricular chamber. Also, since many of the patients for which a CRT device has been implanted have a native left bundle branch block (LBBB) pattern on their surface ECG, the RV capture and native QRS complexes can look remarkably similar. 

A 24-year-old female with dilated cardiomyopathy and clinical VT (unable to pace terminate) at a rate of 150 b.p.m. receives a shock from her ICD without warning while rurming to catch a bus. Her ICD is configured for two zones (a 140-200 b.p.m. VT zone and > 200 b.p.m. VF zone) and there are no SVT/VT discriminators programmed on. You obtain the following EGM tracings for this event as well as a real-time surface lead rhythm strip andEGMs. 

There is intermittent left ventricular capture noted on the rhythm strip (see Case 37 for further explanation). Given this, it was suspected that the left ventricular lead had become slightly dislodged. In fact, by the next morning the left ventricular lead was noted to be completely dislodged out of the coronary sinus anatomy. 

Q Is there anything unusual about the following rhythm strip recorded during this time ... 

Interpreting a rhythm strip is a skill developed through practice. You can use several methods, as long as you re consistent. Rhythm strip analysis requires a sequential and systematic approach. The eight-step method outlined below provides just that. 

The more you look at rhythm strips, the more you ll notice patterns. The symbols below represent some of the patterns you might see as you study rhythm strips. ... 

Looks like a nearly flat line on a rhythm strip except during chest compressions with CPR... 

Left ventricular hypertrophy can lead to heart failure or Ml. The rhythm strips shown here illustrate key ECG changes of left ventricular hypertrophy as they occur in selected leads a large S wave (shaded area in left strip) in and a large R wave (shaded area in right strip) in Vg. If the depth (in mm) of the S wave in added to the height (in mm) of the R wave in Vg exceeds 35 mm, then the patient has left ventricular hypertrophy. 

Obtain 12-lead ECG (when available) or rhythm strip. Is QRS narrow ... 

Miscellaneous antiarrhythmics Adenosine PSVT Adenosine must be administered over 1 to 2 seconds, followed by a 20-ml flush of normal saline solution. Record rhythm strip during administration. Adenosine may cause transient asystole or heart block. 

Each of the 12-leads are displayed on the ECG paper with the appropriate lead name (I, II, III, aVR, aVL, aVF, Vi, V2, V3, V4, V5 and Vg). Each lead is separated by a lead separator/divider marker. A calibration marker is also found at the beginning or end of each line of the ECG. The speed and amplitude may also be found along the bottom the ECG (Fig. 2.2). On many ECGs one of the leads (usually lead II or Vi) is repeated along the bottom of the ECG for the full 12 s. This is used as a rhythm strip. 

Q2. Which of the following leads is commonly used as a rhythm strip at the bottom of a 12-lead ECG ... 

Step 1 Using the rhythm strip at the bottom of the ECG (commonly lead n or Vi), count any 30 large squares (Fig. 4.1). 

Work out the heart rate for the following ECG rhythm strips using the method demonstrated earlier. 

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