Unexplained transient loss of consciousness in a 58 year old male after a Legionella pneumonia: Difference between revisions

Unexplained transient loss of consciousness in a 58 year old male after a Legionella pneumonia (view source)

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 During a Valsalva test there was a large fall in blood pressure with hardly any recovery in pressure during straining  and no overshoot of blood pressure after release of the strain. (Figure 2). Heart rate followed the changes in blood pressure suggesting intact afferent, central and efferent cardiac arterial baroreflex pathways. The lesion therefore appeared to be located in the efferent sympathetic vasoconstrictor pathways.
- Based on the symptoms of orthostatic hypotension and abnormalities in urinary bladder and sexual function autonomic neuropathy was diagnosed clinically and confirmed by autonomic testing. Autonomic neuropathy has been described as a complication of a Legionella infection earlier [1]. The patient received explanation and instructions about his condition (see case 5 in this section).
+ Based on the symptoms of orthostatic hypotension and abnormalities in urinary bladder and sexual function autonomic neuropathy was diagnosed clinically and confirmed by autonomic testing. Autonomic neuropathy has been described as a complication of a Legionella infection earlier<cite>Bernardi</cite>. The patient received explanation and instructions about his condition (see case 5 in this section).
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 == Editor's comments ==
-Lightheadedness induced by exercise is a recognized presenting feature of ischemic heart disease [2]. The referring cardiologist, therefore, was puzzled when he was unable to demonstrate a cardiac abnormality. However, an adequate rise in blood pressure during exercise is not only dependent on normal cardiac function, but also on redistribution of bloodflow. Shunting of oxygenated blood to active muscles does not only result from decreased vascular resistance in active skeletal muscles, but in particularly from strong sympathetic mediated vasoconstriction in non-exercising skeletal muscle and splanchnic and renal vascular beds. Vasoconstriction of these tissues is a prerequisite to obtain an adequate physiological blood pressure increase to exercise. Vasoconstriction,  however, is blunted in patients with autonomic neuropathy [3].
+[[File:TransientLossCons58yoMale_Fig3.jpg | thumb | left | 300px | Figure 3. Comparison of the blood pressure response to supine bicycle exercise in a healthy 56 year old male (upper panel) versus a 61 year old male with orthostatic hypotension due to pure autonomic failure (lower panel). The figure shows the original blood pressure tracing and derived heart rate for both individuals before, during, and after supine leg exercise.  As can be seen blood pressure and heart rate normally increase during supine leg exercise, but blood pressures falls dramatically in the orthostatic hypotension patient with little or no change in heart rate.<cite>Krediet</cite>]]
- Autonomic neuropathy is a rare disorder, but the presentation in this patient is classical [4]. Hypotension during common daily activities in patients with autonomic failure was recognized by earlier investigators. Climbing stairs in particular was noted to elicit symptomatic hypotension [5,6]. The complaints during stair climbing in our patient were at first attributed to his diminished pulmonary function, but laboratory testing disclosed that stair climbing induced symptomatic hypotension [Fig. 1]. The absence of sympathetic vasoconstrictor activity in non-active skeletal muscles and other vascular beds ,  is not compensated for by the increase in cardiac output that occurs during dynamic exercise [7]. As a consequence, blood pressure falls even if the exercise is performed supine, and, as the patient develops muscle fatigue and stops exercising, a further drop in blood pressure occurs [8,9,10]
+Lightheadedness induced by exercise is a recognized presenting feature of ischemic heart disease<cite>Weiner</cite>. The referring cardiologist, therefore, was puzzled when he was unable to demonstrate a cardiac abnormality. However, an adequate rise in blood pressure during exercise is not only dependent on normal cardiac function, but also on redistribution of bloodflow. Shunting of oxygenated blood to active muscles does not only result from decreased vascular resistance in active skeletal muscles, but in particularly from strong sympathetic mediated vasoconstriction in non-exercising skeletal muscle and splanchnic and renal vascular beds. Vasoconstriction of these tissues is a prerequisite to obtain an adequate physiological blood pressure increase to exercise. Vasoconstriction,  however, is blunted in patients with autonomic neuropathy<cite>Rowell</cite>.
-[[File:TransientLossCons58yoMale_Fig3.jpg | thumb | left | 300px | Figure 3. Comparison of the blood pressure response to supine bicycle exercise in a healthy 56 year old male (upper panel) versus a 61 year old male with orthostatic hypotension due to pure autonomic failure (lower panel). The figure shows the original blood pressure tracing and derived heart rate for both individuals before, during, and after supine leg exercise.  As can be seen blood pressure and heart rate normally increase during supine leg exercise, but blood pressures falls dramatically in the orthostatic hypotension patient with little or no change in heart rate.  [Reproduced with permission from 10]]]
-Other frequently reported complaints in patients with autonomic failure are (pre)syncopal symptoms during toilet visits at night and in the early morning [2,3]. This complaint also was present in our patient.
+ Autonomic neuropathy is a rare disorder, but the presentation in this patient is classical<cite>Bannister</cite>. Hypotension during common daily activities in patients with autonomic failure was recognized by earlier investigators. Climbing stairs in particular was noted to elicit symptomatic hypotension<cite>Bradbury</cite><cite>Wieling</cite>. The complaints during stair climbing in our patient were at first attributed to his diminished pulmonary function, but laboratory testing disclosed that stair climbing induced symptomatic hypotension [Fig. 1]. The absence of sympathetic vasoconstrictor activity in non-active skeletal muscles and other vascular beds ,  is not compensated for by the increase in cardiac output that occurs during dynamic exercise<cite>Rowell2</cite>. As a consequence, blood pressure falls even if the exercise is performed supine, and, as the patient develops muscle fatigue and stops exercising, a further drop in blood pressure occurs<cite>Marshall</cite><cite>Smith</cite><cite>Krediet</cite>.
+Other frequently reported complaints in patients with autonomic failure are (pre)syncopal symptoms during toilet visits at night and in the early morning<cite>Weiner</cite><cite>Rowell</cite>. This complaint also was present in our patient.
  In conclusion, in patients with (pre)syncope during exercise combined with miction, defecation, sweating or erectile problems in the absence of cardiac disorders, autonomic dysfunction is likely to be present and autonomic evaluation, including exercise testing and a Valsalva manoeuvre should be performed. By just testing of blood pressure in supine and standing position the diagnosis might be overlooked [9].