just a copy and paste from another forum for future ref...
This Heliamphora disease is caused by a phytopathogenic fungus (which I was able to identify during my molecular studies of Heliamphora by chance), which infects the vascular tissue of the centre of the plant, and can kill a healthy plant within a few days by browning heart disease/ wilt disease. This fungus lives within the tissue of a plant as an endophyte in its asuexual phase (even in wild populations of Heliamphora as it seems), and normally does not harm the plant. However, providing the perfect conditions for the fungus to propagate (which are unfortunately exactly those conditions which will make Heliamphora suffer much, and thus get an easy host for mass infection by the fungus), i.e. prolonged warm temperatures above 28°C and high humidity, the fugus hyphae start growing rapidly, filling all vascular bundels of the plant host's heart (you will recognized dark brown collapsed bundels in the centre of the plant, filled with hyphae under a microscope). The roots and leaves are still looking healthy at this stage, but the plant heart is already dead. It's very characteristic for this wilting disease that the leaves and roots are dying/rotting from the centre to the tip! This means that the tips of the leaves are still fresh and green, whereas the base is already brown and rotting.
I made some infection and growth experiments with this fungus at university in a heated chamber. This fungus can kill a healthy Heliamphora plant at 28°C and high humidity in less than 10 days after infection! On the dying plant parts in the centre of the plant, hundereds of little conidia (asexual spores) are formed for propagation by air and especially water droplets. Interestingly, this fungus is not growing well on artificial growth media, and I did not find any chemical treatment to stop it's growth yet. But I'm still working on this subject, and will keep you updated.
BTW, a related species of fungus is causing almost the same disease in Darlingtonia!
I cannot recommend any cure for infected plants so far (usually the "terminal" stage of this disease is leading to loss of the infected plant, but sometimes regrowth occurs from lateral buds, if growth conditions are changed at once), only preventation:
Cool temperatures (especially during summer heat waves!) seem to be essential, especially cool root temperatures! Spores of this fungus seem to be around everywhere (airborne?), and experienced Heliamphora growers told me that they never had any problems with this wilting disease indoors, when using pure water (not rainwater). This might be due to optimal growing conditions as well.
I only had this problem with Heliamphora grown outdoors or in my greenhouse so far.
All the best,
In some of Wistuba's writings he mentions the temp of 77f as being the threshold...
Personally, I have found a cocktail of Trichoderma atrovirde and Trichoderma virens to be an effective preventative but YMMV. However, once the condition has taken hold there is not much can be done. I have saved a few by digging them up, cutting away all infected material, soaking in trichoderma bath, repotting in new substrate.