electrocardiogram ( ecg ) is an important diagnostic tool for the prompt recognition of myocardial infarction ( mi ) .
identification of st elevation mi by ecg in the critically ill patient population is limited by the lack of specificity due to a variety of non - ischemic processes .
this is a case report of a 77-year - old male patient who presented with generalized weakness , confusion , somnolence , recurrent falls and tea - colored urine for 3 - 4 days .
his past medical history was significant for hypertension , chronic obstructive pulmonary disease and coronary artery disease with a remote history of mi .
his vitals showed blood pressure 97/42 , heart rate of 51 , respiratory rate of 12 and oxygen saturation of 93% on room air .
there were extensive ecchymoses in different stages of healing on all 4 extremities and on the torso .
baseline electrocardiogram during admission to the hospital the patient was rehydrated with intravenous normal saline and nephrotoxic medications were withheld .
his renal function improved and on the 2 day , his chest x - ray revealed patchy bilateral infiltrates . on the 3 day , he developed respiratory distress with an increase in oxygen requirements .
the chest computed tomography revealed bilateral ground glass opacities with consolidation consistent with acute lung injury / acute respiratory distress syndrome . after failing a trial of
non - invasive positive pressure ventilation , he was intubated and mechanically ventilated for hypoxic respiratory failure .
he developed intermittent supraventricular tachycardia , atrial flutter and atrial fibrillation were treated with intravenous esmolol and diltiazem after which he converted to sinus rhythm . on the 4 hospital day , he developed increasing oxygen requirements and asynchronous volume control ventilation ; his ventilator settings were switched to pressure control ventilation .
an echocardiogram revealed left ventricular ejection fraction of 45 - 50% with grade ii diastolic dysfunction and no wall motion abnormalities .
he later became progressively hypoxic and tachypneic on the ventilator during the next couple of days .
his clinical status worsened and his ventilator settings were changed ; the positive end - expiratory pressure ( peep ) was increased to 13 mm hg .
ecg at the time showed st segment and t wave changes concerning for st elevation mi .
careful review of the ecg revealed bizarre , broad - based apparent st - segment elevation in the precordial leads where the upward shift of the baseline started slightly before the onset of the qrs complexes .
a more obvious dome and spike pattern was seen in the inferior leads [ figure 2 ] .
his central venous pressure decreased from 12 to 7 mm hg and tidal volumes were increased from 550 to 750 cc during this period .
an urgent bedside echocardiogram showed preserved left ventricular ejection fraction with no wall motion abnormalities .
the patient passed away on the 11 day of hospitalization from acute respiratory distress syndrome .
st - t segment changes of precordial leads after increase in positive end - expiratory pressure to 13 mm hg .
german military helmet with dome and spike ( inset ) reproduced with permission from mayo clinic proceedings resolution of st - t segment changes in precordial leads after the discontinuation of positive end - expiratory pressure
our case represents an uncommon finding of dome and spike st - t wave changes mimicking st elevation mi in the setting of a critical non - cardiac illness .
these findings were similar to those reported by littmann and monroe and tomcsnyi et al .
the st - t wave changes in these cases were likened to a spiked german military helmet [ inset figure 2 ] the  pickelhaube ,  introduced in 1842 by friedrich wilhelm iv , the king of prussia .
the mechanism of this phenomenon is unknown and several postulated mechanisms for this finding include ( 1 ) artifact ( 2 ) a sudden increase in the intra - abdominal or intra - thoracic pressure ( 3 ) direct stimulation of inferior wall of left ventricle by the diaphragm , ( 4 ) stimulation of the diaphragm by the left phrenic nerve , ( 5 ) synchronized contraction of diaphragm along with the cardiac cycle in the setting of alkalosis with latent tetany , ( 6 ) acute stretch of skin overlying the chest wall with each cardiac cycle and ( 7 ) diaphragmatic breathing that alters ecg patterns .
the acute rise in intrathoracic pressure with an increase in peep most likely contributed to the dome and spike pattern in our patient .
this abnormal ecg finding with a dome and spike  helmet sign  pattern in a critically ill patient is a marker for very high mortality .
it is an under - recognized phenomenon and further research is needed as early recognition can possibly assist clinical management .
 a 77-year - old male patient presented with rhabdomyolysis . 
 he developed progressive respiratory failure and acute respiratory distress syndrome during his hospital stay requiring mechanical ventilation . 
 an electrocardiogram during mechanical ventilation showed findings suggestive of st elevation myocardial infarction . 
 closer review showed dome and spike findings that have been likened to a  spiked helmet .  
 this finding has been associated with significant mortality . 
 we discuss this under - recognized finding and the potential contributing mechanisms . 
Introduction
Case Report
Discussion