Is this normal qt interval 335 and qtc 435 and heart rate 104? ecg showed sinus tachycardia,

HR slightly fast : A hr of 104 at rest (sinus tach) is slightly higher than the normal range of hr's between 60-100 at rest. That said, there could be plenty of reasons that this coud happen (like anxiety, dehydration, caffeine, pain, etc). Also anemia, hyperthyroidism , breathing or pulmonary problems could result in physiologically appropriate faster hr's. Inappropriate sinus tach considered if no cause seen.

Normal QT: A qt of 335 msec and a qtc of 435 msec are normal qt intervals.

QTC a bit Long ?Prob: Question reflects sophistication. Qt prolongation ↑ingly recognized as correlating with a few genetic and/or physiologic issues associated with ↑ed incidence of arrhythmias, sometimes suddenly fatal. However: underlying issues complex, qt varies with rate (reason for qtc), often difficult to read accurately & limited surface indicator. If a concern, best recheck other clues & when rate more normal.