Myocarditis Associated with Influenza A H1N1pdm2009

Table 1

Detailed characteristics of 58 patients with myocarditis associated with H1N1pdm2009 influenza.

Characteristics of 58 patients with H1N1pdm2009 influenza reported in detail	Result (%)
Age (mean, years) (range)	32 (3–72)
Less than 17 years (%)	14 cases (24%)
Sex (% female)	30 cases (52%)
Death (%)	14 cases (24%)
Interval between influenza onset and cardiac symptoms (mean, days) (range)	5.4 (1–21)
1st day to the 3rd day (%)	51%
Cardiac symptoms
Dyspnea (%)	54%
Chest pain (%)	30%
Fulminant myocarditis (%)	36 cases (62%)
Mortality rate of patients with fulminant myocarditis	39% (14/36)
Pneumonia as a complication (%)	13 cases (22%)
ECG findings on the first day of hospitalization
ST elevation (%)	34%
T inversion (%)	24%
Fatal arrhythmias (VF, VT, complete AV block) (%)	22%
Echocardiogram
Diffuse or focal left ventricular wall motion abnormalities	90%
Ejection Fraction (mean ± SD)	25 ± 11%
Percentage of patients in whom CAD was ruled out by CAG	41%
Percentage of adult patients in whom CAD was ruled out by CAG	64%
Treatment
Neuraminidase inhibitors	85%
PCPS	10 cases (17%)
LVAD	1 case (1.7%)
IABP	11 cases (19%)
PCPS or LVAD and/or PCPS	17 cases (29%)
Mortality of patients treated with mechanical support	23% (4/17)
ECMO	12 cases (21%)
Biopsy	10 cases (17%)
Myocarditis with lymphocyte infiltration (mild~moderate)	6 cases
No myocarditis (according to the Dallas criteria)	4 cases
Autopsy	8 cases (14%)
Pachy hemorrhage in the autopsied heart	3/8 cases (38%)
RT-PCR positivity rate for H1N1pdm2009 virus from heart specimens	4 cases

ECG: electrocardiogram; VF: ventricular fibrillation; VT: ventricular tachycardia; AV block: atrioventricular block; CAD: coronary artery disease; CAG: coronary angiography; PCPS: percutaneous cardiopulmonary support; LVAD: left ventricular assist device; IABP: intra-aortic balloon pumping; ECMO: extracorporeal membrane oxygenation; RT-PCR: reverse transcription polymerase chain reaction.