Approach Considerations
Measure systolic blood pressure during ventricular pacing and compare to that during atrial or AV synchronous pacing. A drop of 20 mm Hg or more is suggestive of pacemaker syndrome.
No laboratory studies are indicated.
Begin workup by performing pacemaker interrogation. Rule out excessive ventricular pacing, and look for evidence of AV dissociation or VA conduction. Also rule out pacemaker malfunction, end of battery life, mode reversion for energy conservation, and inappropriate mode switching.
The best method of diagnosis is to correlate patients' symptoms with their cardiac rhythms. This may include use of a Holter monitor or event recorder.
Imaging Studies
Transthoracic echocardiogram may reveal decreased cardiac output with ventricular pacing versus either conducted sinus activity or AV synchronous pacing. M-mode tissue Doppler imaging may reveal an altered ventricular activation pattern.
A study by Lee and associates demonstrated possible utility of transesophageal echocardiography in diagnosis of pacemaker syndrome. They noted higher atrial reverse flow velocities, increased frequency of spontaneous echo contrast in the descending aorta, and significant mitral regurgitation in ventricularly paced patients with pacemaker syndrome. [16]
ECG may reveal a prolonged PR interval, VA conduction, or AV dissociation.
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Pacemaker Syndrome. Pacemaker syndrome without pacemaker participation. Displayed are stored data from a dual-chamber pacemaker. The intracardiac tracings reveal atrial tachycardia with second-degree AV block that together created continuous atrioventricular (AV) dyssynchrony, leading to symptoms of pacemaker syndrome, including fatigue, lightheadedness, and exertional dyspnea. Notice that the pacemaker does not participate in creation of AV dyssynchrony. There are no paced events. Top tracing: atrial electrogram. Middle tracing: ventricular electrogram. Bottom tracing: channel markers. Ab = atrial sensed event in postventricular blanking period, AR = atrial sensed event in postventricular refractory period; VS – Ventricular sensed event.
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Pacemaker Syndrome. Pronounced PR interval prolongation. The effect of this PR interval prolongation on AV dyssynchrony is demonstrated in this ECG image.
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Pacemaker Syndrome. AV dyssynchrony resulting from severe PR interval prolongation in the setting of sinus rhythm. In this ECG, the PR interval is prolonged to the point that the P wave occurs coincident with the peak of the T wave. Compare to the prior image of the same patient with a slower sinus rate.
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Pacemaker Syndrome. Accelerated idioventricular rhythm with retrogradely conducted P waves. This ECG demonstrates a mechanism of AV dyssynchrony that might lead to pseudopacemaker syndrome.
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Pacemaker Syndrome. Junctional rhythm with retrogradely conducted P waves. If symptoms of pacemaker syndrome develop, increasing the lower rate limit for pacing may help to restore AV synchrony.
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Pacemaker Syndrome. Retrogradely conducted P waves are visible directly following each ventricular-paced complex.
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Pacemaker Syndrome. This is an ECG tracing of a patient with continuous atrioventricular synchronous (DDD) pacing prior to development of symptoms. Atrial stimulation (open arrows) is followed by visible P waves. Wide QRS complexes follow ventricular stimulation (solid arrows).
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Pacemaker Syndrome. This is an ECG tracing of a patient with atrioventricular (AV) dissociation and resultant pacemaker syndrome. Native atrial depolarizations (arrows) move progressively closer to pacemaker-stimulated ventricular depolarizations. Ventricular pacemaker stimuli (arrowheads) are greater in amplitude than those visible in the previous image, consistent with mode reversion from AV synchronous (DDD) to ventricular inhibited (VVI), which includes a switch from bipolar pacing (low amplitude) to unipolar pacing (higher amplitude).
Tables
Study |
Patients (number) |
Total Incidence (%) |
Follow-up (years) |
Annual Incidence (%) |
||||
|
|
VVI |
AAI |
DDD |
|
VVI |
AAI |
DDD |
Frielingsdorf [34] |
1838 |
18-47 |
0-17* |
3.75 |
4.8-12.5 |
0-4.5* |
||
Sutton and Kenny [35] |
1061 |
22 |
3.9 |
|
AAI: 2.75 VVI: 3.25 |
6.77 |
1.42 |
|
Hesselson [36] |
8827 |
14-57 |
0-23 |
|
AAI: 1-8 VVI: 3-8 |
Cannot be determined |
||
Hesselson [36] |
950 |
38 |
7 |
|
7 |
5.43 |
1.00 |
|
Santini [37] |
339 |
48 |
3.7 |
13 |
5 |
9.6 |
0.74 |
2.6 |
Sasaki [38] |
75 |
41 |
2* |
AAI: 3.25 VVI: 5.17 |
7.9 |
0.62* |
||
Rosenqvist [39] |
168 |
47 |
6.7 |
|
4 |
11.8 |
1.68 |
|
*Combined AAI and DDD |
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