Tag Archives: diagnosis

Characteristic ECG signs of LAD occlusion without ST elevation

In a single centre observational study over 10 years of patients undergoing acute PCI of the left anterior descending (LAD) artery, 35 of 1890 (2%) had a distinct non-ST elevation ECG pattern.

The ECG showed ST-segment depression at the J-point of at least 1 mm in the precordial leads with upsloping ST-segments continuing into tall, symmetrical T-waves. Patients also showed a mean J-point elevation of approximately 0.5 mm in lead aVR.

This novel ECG pattern resolved after reperfusion in all included patients.

The authors caution that these electrocardiographic changes may be missed or misdiagnosed as reversible ischaemia, which might substantially delay the transportation to a PCI centre or the start of reperfusion therapy

The authors conclude: “It is important for cardiologists and emergency care physicians to recognise this distinct ECG pattern, so they can triage such patients for immediate reperfusion therapy.”

Image from Dr Smith's ECG Blog

Persistent precordial “hyperacute” T-waves signify proximal left anterior descending artery occlusion
Heart. 2009 Oct;95(20):1701-6

Rectal exam has lousy test characteristics

A comprehensive review of the literature, the findings of which showed ‘compelling’ consistency: digital rectal examination (DRE) as a screening test had sensitivities ranging from 0% to 50%, had consistently high false-positive and false-negative rates, and did not improve the predictive value of the other components of a typical trauma examination.

Based on case reports of five patients, the authors suggest DRE may be of value during trauma evaluation in the following settings: (1) patients with evidence of penetrating trauma in the vicinity of the rectum, (2) cases in which the presence of neurologic injury is neither completely supported nor refuted by the clinical findings, and (3) before pharmacologic paralysis. A selective approach is therefore recommended. Some good news for your patients if this will persuade you to discard another piece of longstanding dogma perpetuated in basic trauma teaching.

Should the digital rectal examination be a part of the trauma secondary survey?
Ann Emerg Med. 2009 Feb;53(2):208-12

End expiratory occlusion

OBJECTIVE: During mechanical ventilation, inspiration cyclically decreases the left cardiac preload. Thus, an end-expiratory occlusion may prevent the cyclic impediment in left cardiac preload and may act like a fluid challenge. We tested whether this could serve as a functional test for fluid responsiveness in patients with circulatory failure.

DESIGN: Prospective study.

SETTING: Medical intensive care unit.

PATIENTS: Thirty-four mechanically ventilated patients with shock in whom volume expansion was planned.

INTERVENTION: A 15-second end-expiratory occlusion followed by a 500 mL saline infusion.

MEASUREMENTS: Arterial pressure and pulse contour-derived cardiac index (PiCCOplus) at baseline, during passive leg raising (PLR), during the 5-last seconds of the end-expiratory occlusion, and after volume expansion.

MAIN RESULTS: Volume expansion increased cardiac index by >15% (2.4 +/- 1.0 to 3.3 +/- 1.2 L/min/m, p < 0.05) in 23 patients ("responders"). Before volume expansion, the end-expiratory occlusion significantly increased arterial pulse pressure by 15% +/- 15% and cardiac index by 12% +/- 11% in responders whereas arterial pulse pressure and cardiac index did not change significantly in nonresponders. Fluid responsiveness was predicted by an increase in pulse pressure >or=5% during the end-expiratory occlusion with a sensitivity and a specificity of 87% and 100%, respectively, and by an increase in cardiac index >or=5% during the end-expiratory occlusion with a sensitivity and a specificity of 91% and 100%, respectively. The response of pulse pressure and cardiac index to the end-expiratory occlusion predicted fluid responsiveness with an accuracy that was similar to the response of cardiac index to PLR and that was significantly better than the response of pulse pressure to PLR (receiver operating characteristic curves area 0.957 [95% confidence interval [CI:] 0.825-0.994], 0.972 [95% CI: 0.849-0.995], 0.937 [95% CI: 0.797-0.990], and 0.675 [95% CI: 0.497-0.829], respectively).

CONCLUSIONS:The hemodynamic response to an end-expiratory occlusion can predict volume responsiveness in mechanically ventilated patients.

Predicting volume responsiveness by using the end-expiratory occlusion in mechanically ventilated intensive care unit patients.
Crit Care Med. 2009 Mar;37(3):951-6